Как выглядит номер телефона сша

Я регю аккаунт в paypal.Указал страну америка.Там просят ввести номер телефона .Левый не проходит.Или есть другая страна с которой можно зарегиться без проверки на номер ?
Только западная.

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Добавлено модератором:

  1. Формат американского стационарного и мобильного номера телефона, варианты написания и примеры
  2. Где взять американский номер телефона для регистрации на американских сайтах
  3. Виртуальный номер телефона США с возможностью принимать звонки и СМС

Большинство людей, пользующихся услугами почтового посредника (майлфорвардера) в США, заказывают товары самостоятельно, указывая адрес склада вместо своего почтового адреса. Отдельным пунктом адреса является телефонный номер. Имеет ли значение номер телефона, как его указывать – в данном топике.

Формат американского стационарного и мобильного номера телефона, варианты написания и примеры

Стандарт нумерации телефонов США приведен к международной системе. Каждый номер начинается с +1 – это так называемый «код страны», аналогичный российскому +7. Помимо США, этот код использует Канада и большинство стран Карибского бассейна.

Следом идет код территории – трехзначный номер, начинающийся с цифр от 2 до 9. Например, 202 – код столицы США, города Вашингтон, а 302 – код штата Делавэр. За ним – сервисный код такого же формата, определяющий конкретного оператора.

После трех кодов следует непосредственно номер абонента – четыре цифры из диапазона 0000 – 9999. Таким образом, полный номер абонента имеет 11 знаков, но для внутренних звонков чаще используются сокращенные десятизначные варианты (без кода страны), либо семизначные (внутри кода территории). Полные номера, как правило, записываются в формате +1 (XXX) XXX-XXXX, или 1-XXX-XXX-XXXX.

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Примечательно, что

американские мобильные номера не имеют выделенного префикса

, используя те же коды территорий. Помимо этого, американцам доступен перенос номера с мобильного оператора на стационарного, и наоборот. Поэтому быстро определить категорию номера довольно тяжело.

Где взять американский номер телефона для регистрации на американских сайтах

Практически во всех американских интернет-магазинах требуется телефонный номер при заполнении почтовых данных. Правда, его необходимость достаточно условная – магазин не будет звонить без веской причины на это, в 99% случаев коммуникация происходит посредством электронной почты.

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Указание именно американского номера необходимо нерезидентам США для регистрации на адрес посредника, поэтому в таких случаях лучше всего использовать номер, который мейлфорвардер назначил для вашего почтового адреса. Зачастую такие номера имеют довольно фиктивное значение, будучи указанными просто «для галочки».

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Можно использовать другой американский номер для регистрации (своя симка из США, номер друга/родственника) – это не возбраняется. Однако номер придется подогнать под международный 11-значный формат, общепринятого вида: +1 (XXX) XXX-XXXX или +1-XXX-XXX-XXXX.

Виртуальный номер телефона США с возможностью принимать звонки и СМС

Существует множество сайтов и приложений, предоставляющих (платно или бесплатно) виртуальный номер конкретного государства. В отличии от VoIP-телефонии, о которой рассказано в топике «Как дешево звонить из России в Украину?», эти сервисы выдают почти полноценные телефонные номера. С них можно не только звонить, но и принимать входящие звонки и смс-сообщения.

Их используют для связи с близкими, и как дополнительный личный номер. Стоит заметить – большинство этих сервисов не разрешают прием сообщений с коротких номеров, или с буквенных адресантов, поэтому использовать их для регистрации на сторонних ресурсах не получится.

Сотовая связь уже давно стала популярней, чем обычные городские номера, и пользуется ей практически каждый. Само собой, это касается в том числе и американских абонентов. Мобильные номера США отличаются от того, что мы привыкли видеть в других странах. Давайте посмотрим, как может выглядеть стандартный американский мобильный номер, и какие особенности характерны для сотовой телефонии в этой стране.

Фото: istockphoto.com

Основная информация

В отличие от почти любой другой страны, сотовые номера Америки не разграничиваются каким-то специальным образом от стационарных. Они просто пишутся точно так же, как и обычные номера. Таким образом, вы не можете определить, является ли тот или иной абонент держателем мобильного или обычного телефона, только по его номеру.

Практически повсюду в мире номера сотовых имеют свой уникальный префикс, по которому мы понимаем, что это именно мобильник. Например, в России это 9ХХ, Великобритании это 7XX, в Австралии – 4XX, во Франции – 6XX и так далее.

Мобильным номерам Америки дается обычный номер абонента в коде географической зоны (номера), где был приобретен телефон или SIM-карта. Причины этого не совсем известны. Но скорее всего главная причина заключается в следующем: это уходит корнями в то, как сотовая сеть была изначально развернута в США.

Дело возможно в том, что изначально, на заре развития беспроводной связи в конце 1980-х годов, американские операторы обслуживали абонентов, только если те находились в географическом коде города или штата, где был куплен телефон. По этой причине тогда также существовали устройства для оповещения, чтобы предупреждать пользователей, когда кто-то хотел с ними связаться. С тех пор, разумеется, многое изменилось, и уже давно можно звонить и принимать звонки, находясь, где угодно. Однако сам принцип привязки кода к определенному региону остался.

Не существует американского формата отдельно мобильных номеров. Все потому, что мобильные телефоны получают номера в тех же географических кодах, что и стационарные.

Все телефоны в США используют один формат: (NXX) NXX-XXXX, где N это 2–9, а X – 0–9. Это характерно для всех примерно 20 стран, участвующих в Североамериканском плане нумерации (код страны +1).

Структура номера

Стандартный номер мобильного телефона в США состоит из десяти цифр, например (555) 555-1234. Первые три цифры – это «код города», который раньше указывал, в какой части страны находился телефон. В настоящее время с ростом популярности сотовых телефонов люди в одной части страны могут иметь телефоны с кодами из другой части страны (поскольку эти телефоны были куплены там).

+1 NXX-NXX-XXXX – пример мобильный номер США, а точнее, его структуры.

N = цифры 2–9, X = цифры 0–9

+1 – это код страны. Что интересно, помимо Соединенных Штатов, есть еще около 20 стран, например, Канада, некоторые государства Карибского бассейна), которые используют этот же код.

Первые 3 цифры, NXX, – это код города, который соответствует географическому региону, например городу или графству. Иногда он может обозначать услугу, например бесплатный звонок (также известный как бесплатный телефон, аналог российских номеров 8-800).

Следующие 3 цифры называются кодом центрального офиса. NXX-NXX обозначает конкретного поставщика услуг (оператора связи) и коммутатор для целей маршрутизации. Полные 10 цифр называются номером строки, которые назначаются пользователям. Так что, вот такие интересные особенности есть у сотовых номера США. И если вы периодически общаетесь с абонентами из этой страны, будет интересно об этом знать.

Мы привыкли записывать телефонный номер, начиная с восьмерки. Поэтому когда где-либо требуется записать или ввести на сайте номер телефона в международном формате, то сразу в голове масса вопросов.

Подробно рассказываем, как набрать номер телефона в международном формате, и откуда вообще взялся этот формат.

Российские номера сотовых телефонов в международном формате состоят из трех элементов:

  • +7 — международный код страны, Российской Федерации;
  • ХХХ — три цифры, обозначающих префикс. Эти три цифры определяют название сотового оператора и регион регистрации номера;
  • ХХХ-ХХ-ХХ — семь уникальных цифр, номер абонента, по которому также можно определить регион.

Отметим, что если речь идет про городской телефон, то может отличаться количество цифр в абонентском номере. Если в крупных городах географический код всегда состоит из трех цифр, то в других населенных пунктах он может включать четыре или пять цифр. Однако общее число цифр не изменится — код и номер абонента всегда состоит из десяти цифр. Поэтому, если региональный код четырехзначный, то абонентский номер включает шесть цифр, а если пятизначный код города, то пять.

Итак, чтобы записать номер в международном формате, следует набрать 11 цифр, не считая знака плюсика. Эта комбинация используется для звонков из зарубежных стран в Россию, внутри страны можно звонить, набирая вместо +7 восьмерку. В книге контактов лучше сразу сохранять номера в международном формате, потому что зачастую звонки через восьмерку не проходят, а также сможете гарантированно дозвониться на нужный номер, находясь в любой стране.

Правила набора номера в международном формате<br>

Номер «Мегафон» в международном формате имеет префиксы 920-929, 936 и 937. Номера МТС в международном формате отличаются префиксом 910-919, 980-989. Номера «билайн» в международном формате легко узнать по префиксам 903-909, 961-968, 976.

Однако стоит учитывать, что номера в одном коде могут быть разделены регулятором между несколькими операторами. Это связано с тем, что номерной ресурс ограничен, и выделить всем операторам, а их зарегистрировано более ста, коды с необходимым количеством номеров, невозможно.

Строго говоря, любые российские сотовые номера сразу пишутся в международном формате, так как без кода страны и кода оператора позвонить по ним невозможно.

Важно знать, что телефонный код +7 Россия разделяет с Казахстаном и Абхазией, а также мобильными номерами Южной Осетии. Другие республики после распада Союза перешли на собственные коды. Крым также использует российские коды +7-869 (местная связь в Севастополе), а сотовые номера Крыма в международном формате начинаются с комбинации +7978.

В международном формате можно набрать и любой городской (местный) номер. Если вам нужно позвонить, к примеру, в отель за рубежом, со стационарного телефона следует набрать 8-10-{код страны}-{код города}- номер абонента. А вот с сотового номера нужно набирать вместо 8-10 — плюс и код страны.

Как позвонить в другую страну из России<br>

Цифра +7 определяет принадлежность номера к российской телефонной сети. Для других стран зарезервированы иные коды. Американский сотовый номер выглядит так:

+1 {код страны} ХХХ {код штата или города} ХХХХ-ХХ-ХХ {номер абонента}

Каждый штат США имеет свой префикс, а вот привязки номера телефона к оператору в США не существует. В одном штате может быть несколько вариаций префиксов.

Например, в Нью-Йорке используются коды 347, 212 и 646. В то же время, абонент с этим номером может переехать в какой угодно штат, роуминга внутри страны нет, так что по этим цифрам можно определить только, в каком штате номер был впервые зарегистрирован.

Также цифры, идущие после +1 в международном американском номере, позволяют определить, со стационарного или сотового номера вам звонят. К примеру, 212 код стационарной сети Нью-Йорка (но не в 100% случаев).

Как видим, американский номер в международном формате также включает 11 цифр. А вот украинский длиннее: здесь код соединения со страной состоит из трех цифр, +380. Украинские мобильные номера в международном формате выглядят так:

+380 {код страны} ХХ {код оператора} ХХХ-ХХ-ХХ {номер абонента}

У каждого сотового оператора Украины, соответственно, свои коды:

  • 63, 73 и 93 — коды оператора Lifecell;
  • 50, 66, 95, 99 — Vodafone;
  • 67, 68, 69, 96, 97, 98 — префиксы для звонков в сети Киевстар;
  • 91 — ТриМоб;
  • 92 — PEOPLEnet;
  • 94 — Интертелеком.

Отличается в стране формат национального набора. Как и в других странах Европы, вместо привычной нам восьмерки, используется ноль. Им можно заменить +380 при наборе номера, если звонок совершается внутри страны.

Белорусские сотовые телефоны в международном формате легко определить по начальным цифрам +375.

Хотя у Казахстана код страны совпадает с Россией, их номера определяются по префиксу: они имеют формат +7(6xx)xxx-xx-xx или +7(7xx)xxx-xx-xx. Префиксы российских сотовых операторов принадлежат исключительно диапазону (9хх).

Отметим, что на территории страны также действует нумерация с кодом начинающимся на восьмерку. Также, как в России, это специальные многоканальные номера. К примеру, 800 для бесплатных звонков с любого казахстанского номера.

Как появился международный формат нумерации<br>

Последовательность набора номера определяется телефонным планом нумерации — унифицированной системой, позволяющей пользователям сети отправлять и принимать звонки, а также определять звонящего (услуга определения номера включена во все тарифные планы сотовых операторов).

В мире существует два плана нумерации: открытый и закрытый. При первом местные вызовы можно совершать без национального номера (кода города), а при втором, то есть закрытом, необходимо набирать полный международный формат номера для звонка любого вида: местного, междугороднего, международного, либо национальный — в России это восьмерка вместо кода страны.

В основном страны применяют закрытый план нумерации, Москва сегодня полностью переведена на него. Отметим, что популярный термин “прямой номер” появился до того, как введен закрытый план. “Кривым”, на самом деле, является не номер с городским кодом, а тот, что можно набирать напрямую без кода города/оператора.

По планам Министерства цифрового развития, к 2020 году Россия должна была полностью перейти на закрытый план нумерации, но пока данный процесс не завершен. Это означает, что со временем во все городах нельзя будет набирать короткие 5-7-значные номера для местных вызовов, а всегда будет необходимо использовать полный международный формат номера.

Также планируется переход на международную систему национального формата номеров. По планам Минцифры, замена восьмерки на ноль будет произведена до 2025 года.

Сейчас у нас есть различие в наборе комбинаций при звонках внутри телефонной зоны, за ее пределы и при междугородних вызовах.

  • ХХХ-ХХ-ХХ — звонки по местным городским номерам, никакие коды не нужны;
  • 8 (Код города) ХХХ-ХХ-ХХ — междугородные звонки, набираются с кодом города;
  • +7 (код города) (номер абонента) — для звонков из-за пределов РФ.

Если говорить о вызовах со стационарных телефонов, то для выхода на межгород нужно набирать 8-ку (в других странах 0).

При закрытом плане нумерации всегда нужно будет набирать расширенный вариант, то есть с +7 и кодом города, либо пользуясь национальным форматом.

Страны редко меняют план нумерации, но в ближайшем будущем это предстоит россиянам. Большинство абонентов не почувствуют разницы, ведь в телефонной книге смартфона удобно сразу сохранять длинную версию номера, лишь только редким пользователям стационарных телефонов придется всегда набирать длинные номера в международном формате.

Именно поэтому рекомендуем сохранять контакты в записной книжке своего телефона в международном формате. Такое простое правило позволит позвонить на любой номер, как находясь в России, так и за ее пределами. Тарификация звонков не отличается — стоимость минуты одинаковая как при наборе номера с +7, так и начиная с восьмерки.

Российский номер сотового телефона в международном формате состоит из 11 цифр, где +7 — это международный идентификатор страны, (9хх) — префикс оператора, также показывающий регион регистрации номера, а дальше идет семизначный номер абонента.

Для правильного набора местных номеров в международном формате нужно предварительно выяснить код города.

NANP countries.svg

Countries participating in the NANP

Format +1 NXX NXX-XXXX
Access codes
Country calling code 1
International call prefix 011
List of dialing codes

The North American Numbering Plan (NANP) is a telephone numbering plan for twenty-five regions in twenty countries, primarily in North America and the Caribbean. This group is historically known as World Zone 1 and has the international calling code 1. Some North American countries, most notably Mexico, do not participate in the NANP.

The concepts underlying the NANP were originally devised in the 1940s by the American Telephone and Telegraph Company (AT&T) for the Bell System and the independent telephone operators in North America. The goal was to unify the diverse local numbering plans that had been established in the preceding decades, speed call completion times, and reduce costs for toll calls, by reducing or eliminating manual labor by telephone operators, and eventually prepare the continent for direct-dialing of long-distance calls by customers. Direct dialing became possible in 1951 in a first trial, and was expanded across the nation in the decade following. AT&T continued to administer the numbering plan and the technical infrastructure until the breakup of the Bell System, when administration was delegated to the North American Numbering Plan Administrator (NANPA), a service that has been procured from the private sector by the Federal Communications Commission (FCC) in the United States. Each participating country forms a regulatory authority that has plenary control over local numbering resources.[1] The FCC also serves as the U.S. regulator. Canadian numbering decisions are made by the Canadian Numbering Administration Consortium.[2]

The NANP divides the territories of its members into numbering plan areas (NPAs) which are encoded numerically with a three-digit telephone number prefix, commonly called the area code.[3] Each telephone is assigned a seven-digit telephone number unique only within its respective numbering plan area. The telephone number consists of a three-digit central office (or exchange) code and a four-digit station number. The combination of an area code and the telephone number serves as a destination routing address in the public switched telephone network (PSTN). The North American Numbering Plan conforms with International Telecommunication Union (ITU) Recommendation E.164, which establishes an international numbering framework.[4]

History[edit]

Area code handbook issued by many telephone companies in 1962 to promote the newly introduced direct distance dialing

From the Bell System’s beginnings in 1876 and throughout the first part of the 20th century, telephone networks grew from essentially local or regional telephone systems. These systems expanded by growing their subscriber bases, as well as increasing their service areas by implementing additional local exchanges that were interconnected with tie trunks. It was the responsibility of each local administration to devise telephone numbering plans that accommodated the local requirements and growth.[5] As a result, the North American telephone service industry developed into an unorganized set of many differing local numbering systems. The diversity impeded the efficient operation and interconnection of exchanges into a nationwide system for long-distance telephone communication. By the 1940s, the Bell System set out to unify the various existing numbering plans to provide a unified, systematic approach for routing telephone calls across the nation and to provide efficient long-distance service that eventually did not require the involvement of switchboard operators.

In October 1947, AT&T published a new nationwide numbering plan in coordination with the independent telephone operators. The plan divided most of North America into eighty-six numbering plan areas (NPAs). Each NPA was assigned a unique three-digit code, typically called NPA code or simply area code. These codes were first used in Operator Toll Dialing by long-distance operators in establishing calls via trunks between toll offices. The goal of automatic service required additional technical advancements in the latest generation of toll-switching systems, completed by the early 1950s, and installation of new toll-switching systems in most numbering plan areas. The first customer-dialed direct call using an area code was made on November 10, 1951, from Englewood, New Jersey, to Alameda, California.[6] Direct distance dialing (DDD) was subsequently introduced across the country. By the early 1960s, DDD had become commonplace in cities and most towns in the United States and Canada. By 1967, the number of assigned area codes had grown to 129.[7]

The status of the network of the 1960s was reflected in a new name used in technical documentation: North American Integrated Network.[7] By 1975, the numbering plan was referred to as the North American Numbering Plan,[8] leading to the well-known acronym NANP, as other countries sought or considered joining in the standardization.

Foreign expansion[edit]

Although Bermuda and the Caribbean islands had been assigned the area code 809 as early as 1958 by the administrators at AT&T, individual participating countries or territories had no autonomy over their numbering plan as they received centrally assigned central office prefixes that needed to be unique from those of other countries with the same area code. Regions in Mexico with high call volumes to and from the US were assigned functional area codes as early as 1963, for the purpose of call routing, but a nationwide system of participation in the NANP eventually failed.

In the following decades, the NANP expanded to include all of the United States and its territories, Canada, Bermuda, and seventeen nations of the Caribbean.[9][10]

At the request of the British Colonial Office, the numbering plan was first expanded to Bermuda and the British West Indies because of their historic telecommunications administration through Canada as parts of the British Empire and their continued associations with Canada, especially during the years of the telegraph and the All Red Line system.

Not all North American polities participate in the NANP. Exceptions include Mexico, Greenland, Saint Pierre and Miquelon, the Central American countries and some Caribbean countries (Cuba, Haiti, the French Caribbean and the Dutch Caribbean, except for Sint Maarten). The only Spanish-speaking state in the system is the Dominican Republic. Mexican participation was planned,[11] but implementation stopped after three area codes (706, 903 and 905) had been assigned, and Mexico opted for an international numbering format, using country code 52.[12] The area codes in use were subsequently withdrawn in 1991.

The Dutch Caribbean territory of Sint Maarten joined the NANP in September 2011, receiving area code 721.[13] Sint Maarten shares the island with the French Collectivity of Saint Martin which, like the rest of the French Caribbean, is not part of the NANP.

Administration[edit]

The NANP is administered by the North American Numbering Plan Administrator (NANPA, formerly Administration).[14] This function is overseen by the Federal Communications Commission, which assumed the responsibility upon the breakup of the Bell System. The FCC solicits private sector contracts for the role of the administrator.

Before the breakup of the Bell System, administration of the North American Numbering Plan was performed by AT&T’s Central Services Organization. In 1984, this function was transferred to Bell Communications Research (Bellcore), a company created by the divestiture mandate to perform services for the newly created local exchange carriers. On January 19, 1998, the NANPA function was transferred to the IMS division of Lockheed Martin in Washington, D.C.[15] In 1999, the contract was awarded to Neustar, a company spun off from Lockheed for this purpose. The contract was renewed in 2004, and again in 2012.[16] On January 1, 2019, Somos assumed the NANPA function under a one-year bridge contract granted by the FCC with the goal of consolidating the NANPA function with the Pooling Administrator and identifying a long-term contract holder.[17][18] On December 1, 2020, Somos secured the $76 million contract for a term of eight years against one other bidder.[19]

Numbering plan[edit]

The vision and goal of the architects of the North American Numbering Plan was a system by which telephone subscribers in the United States and Canada could themselves dial and establish a telephone call to any other subscriber without the assistance of switchboard operators. While this required an expansion of most existing local numbering plans, many of which required only four or five digits to be dialed, or even fewer in small communities, the plan was designed to enable local telephone companies to make as few changes as possible in their systems.

Numbering plan areas and central offices[edit]

The new numbering plan divided the North American continent into regional service areas, called numbering plan areas (NPAs). The divisions primarily followed the jurisdictional boundaries of the U.S. states and the Canadian provinces.[20] Some states or provinces needed to be divided into multiple areas. NPAs were created in accordance with principles deemed to maximize customer understanding and minimize dialing effort, while reducing plant cost.[21] Each NPA was identified by a unique three-digit code number that was prefixed to the local telephone number, when calling from one NPA to another. Within the same numbering plan area, dialing the area code was not necessary.

The telephone exchanges—in the Bell System they were officially called central offices—became local exchange points in the nationwide system. Each of them was also assigned a three-digit number unique within its NPA. The combination of NPA code and central office code served as a destination routing code for use by operators to reach any central office through the switching network.[20] Due to the numerical structure of the numbering system, each NPA was technically limited to 540 central offices.[21]

Although the limitation to 540 central offices required the most populous states to be divided into multiple NPAs, it was not the sole reason to subdivide a state. An important aspect was the existing infrastructure for call routing, which had developed in preceding decades independently of state boundaries. The rules of determining areas also attempted to avoid cutting across busy toll traffic routes, so that most toll traffic remained within an NPA, and outgoing traffic in one area would not be tributary to toll offices in an adjacent area.[22][20] As a result, New York state was initially divided into five areas, the most of any state. Illinois, Ohio, Pennsylvania, and Texas were assigned four NPAs each, and California, Iowa, and Michigan received three. Eight states and provinces were split into two NPAs.

Traditionally, central office switching systems were designed to serve up to ten thousand subscriber numbers. Thus, subscribers were assigned four-digit line or station numbers. This rounded out the total number of digits in a subscriber telephone number to ten: a three-digit area code, three-digit central office code, and four digits for each line. This fixed format defined the North American Numbering Plan as a closed numbering plan,[23] as opposed to developments in other countries where the number of digits was not fixed.

The closed numbering plan did not require the subscriber to dial all digits. When making a local call or a call within the same numbering plan area, the area code was omitted, resulting in seven-digit dialing. Ten-digit dialing was only necessary when placing foreign area calls to subscribers in another state or numbering plan area.[24] Exceptions existed for communities located on NPA boundaries, so that uniform local dialing was still possible in historically established communities.

Initial numbering system[edit]

In 1947, AT&T completed the new design for a nationwide toll network that established the original North American area codes. The new organization provided for 152 area codes, each with a capacity to serve up to 540 central offices.[25] Originally, only eighty-six area codes were assigned. New Jersey received the first NPA code in the new system, area code 201.[26] The second area code, 202, was assigned to the District of Columbia. The allocation of area codes was readjusted as early as 1948 to account for inadequacies in some metropolitan areas. For example, the Indiana numbering plan area 317 was divided to provide a larger numbering pool in the Indiana suburbs of Chicago (area code 219).

Initially, states divided into multiple numbering plan areas were assigned area codes with the digit 1 in the second position, while areas that comprised entire states or provinces received codes with 0 as the middle digit. This rule was broken by the early 1950s,[20] as NPAs with digit 0 in the middle had to be split, but until 1995 all area codes assigned had none other than the digits 0 and 1 in this position.

The eight codes of the form N11 (N=2–9) were reserved as service codes. The easily recognizable codes of the form N00 were available in the numbering plan, but were not initially included in assignments.[7] Additional area code patterns were later assigned for other services; for example, the area codes N10 were implemented for the Teletypewriter Exchange Service (TWX).[27]

Central office codes[edit]

It was already common practice for decades that the digits 0 and 1 could not appear in the first two digits of the central office codes, because the system of using the first two letters of familiar names for central offices did not assign letters to these digits. The digit 0 was used for operator assistance, and 1, which is essentially a single pulse of loop interruption, was automatically ignored by most switching equipment of the time.[20] Therefore, the 0/1 rule for the area code provided a convenient means to distinguish seven-digit dialing from ten-digit dialing.

The use of telephone exchange names as part of telephone numbers had been a well-established practice, and this was preserved for convenience and expediency in the new network design. The letter-to-digit translations were printed on the face of every rotary dial in the metropolitan areas, according to a scheme designed by W.G. Blauvelt in 1917, that had been used in the Bell System in large metropolitan areas since the early 1920s.[28] The network reorganization standardized this system to using a two-letter, five-digit (2L-5N) representation of telephone numbers in most exchanges in North America,[29] or to using an equivalent all-numeric seven-digit numbering plans, as was practiced by some telephone companies.

All-number calling[edit]

Partitioning of the NANP prefix space
under all-number-calling
000 — 099 These 200 codes were used
as toll center and system codes.
100 — 199
area
codes
service
codes
area
codes
central office
codes
200 — 210 211 212 — 219 220 — 299
300 — 310 311 312 — 319 320 — 399
400 — 410 411 412 — 419 420 — 499
500 — 510 511 512 — 519 520 — 599
600 — 610 611 612 — 619 620 — 699
700 — 710 711 712 — 719 720 — 799
800 — 810 811 812 — 819 820 — 899
900 — 910 911 912 — 919 920 — 999
152 area codes
8 special service codes
640 CO codes

All-number calling was a telephone numbering plan introduced in 1958,[30] that converted telephone numbers with exchange names to a numeric representation of seven digits.

The original plan of 1947 had been projected to be usable beyond the year 2000. However, by the late 1950s it became apparent that it would be outgrown by about 1975.[31] The limitations for the usable leading digits of central office codes, imposed by using common names for central office names, and their leading two characters as guides for customer dialing could no longer be maintained when opening new central offices. By 1962 it was forecast that in 1985 the number of telephones in the nation would equal its population of 280 million and increase to 600 million telephones for 340 million people in 2000.[29] As a result, the North American telephone administrations first introduced letter combinations that could not be linked to a familiar pronounceable central office name. Finally, they sought the elimination of central office names and letter codes, and introduced all-number calling (ANC).

Under all-number calling, the number of permissible central office prefixes increased from 540 to potentially 800, but the first two digits of the central office code were still restricted to the range 2 to 9, and the eight combinations that ended in 11 were reserved as special calling codes.[29] This increased the numbering pool for central office codes to 640, and resulted in the partitioning of the prefix space (000999).[32]

Interchangeable central office codes[edit]

As the numbering plan grew in the 1960s under all-number calling, plan administrators at AT&T identified that by c. 1973 some of the largest area codes in urban centers might run out of central office prefixes to install more individual access lines. For relief in these cases, they finally removed the requirement that the middle digit of the central office code could not be 0 or 1. This resulted in the format of interchangeable central office codes, N X X, where N=2–9 and X=0–9. The first cities that required this action, in 1974, were the cities of Los Angeles with area code 213 and New York with 212. This change also required modification of the local dialing procedures to distinguish local calls from long-distance calls with area codes.

Requiring 1 to be dialed before the full number in some areas provided for area codes of the form N10, such as 210 in the San Antonio, Texas, area and 410 in eastern Maryland. Therefore, someone calling from San Jose, California, to Los Angeles before the change would have dialed 213-555-0123 and after the change 1-213-555-0123, which permitted the use of 213 as an exchange prefix in the San Jose area. The preceding 1 also ideally indicates a toll call; however, this is inconsistent across the NANP because the FCC has left it to the U.S. state public utilities commissions to regulate for traditional landlines, and it has since become moot for mobile phones and digital VoIP services that now offer nationwide calling without the extra digit.[citation needed]

Interchangeable NPA codes[edit]

In 1995, the North American Numbering Plan Administrator removed the requirement that the middle digit of an area code had to be either 0 or 1, implementing fully interchangeable NPA and central office codes, that had already been anticipated since the 1960s, when interchangeable central office codes were sanctioned.

Modern plan[edit]

The NANP numbering format may be summarized in the ten-digit notation NXX NXX-XXXX, where the Ns denote any of the digits 2–9, and the Xs denote any digit 0–9.

Component Name Number ranges Notes
NXX
often denoted NPA
Numbering plan area code The first NXX block is the numbering plan area code. When the second and third digits are the same, the code is an easily recognizable code (ERC). ERCs designate special services; e.g., 800 for toll-free service. The NANP is not assigning area codes with 9 as the second digit.[33] Covers Canada, the United States, parts of the Caribbean Sea, and some Atlantic and Pacific islands. The area code is often enclosed in parentheses.
NXX Central office code The second NXX block is the central office code. Permissible numbers exclude easily recognizable codes N11, used for special services. Also called exchange code
XXXX Line number A unique four-digit number for each NPA, from 0000 to 9999 Also called station code

Using 0 or 1 as the first digit of an area code or central office code is invalid, as is a 9 as the middle digit of an area code; these are trunk prefixes or reserved for North American Numbering Plan expansion.

For example, (234) 235-5678 is a valid telephone number; with area code 234, central office prefix (exchange) 235, and line number 5678. The number (234) 911-5678 is invalid, because the central office code must not be in the form N11. (314) 159-2653 is invalid, because the office code must not begin with 1. (123) 234-5678 is invalid, because the NPA must not begin with 0 or 1.[34][35][36][37]

Each three-digit area code has a capacity of 7,919,900 telephone numbers (7,918,900 in the United States).

Despite the widespread use of fictional telephone numbers of the form NXX 555-XXXX, only the block of line numbers from 0100 through 0199 are specifically reserved for this purpose, leaving the rest available for assignment.

The country calling code for all countries participating in the NANP is 1. The prefix 1 is also used with the NANP for long-distance dialing.

Non-geographic services[edit]

The North American Numbering Plan recognizes the need for non-geographic services by designating certain numbering blocks for such purposes. Many of these telephone numbers are selected from the easily recognizable codes (ERCs).

For system-wide toll-free calling, in which the receiving party is billed for the call, uses the number range with area codes of the form 8XX.

Area code and central office prefixes for other non-geographic services have the form 5XX-NXX. As of January 2021, the codes 500, 521, 522, 533, 544, 566, 577, 588, 523, 524, 525, and 526 have been designated.[38] These codes are used for fixed or mobile devices, and not assigned to rate centers. As addresses, they may or may not traverse the public switched telephone network (PSTN). Applications include the use as personal 500 numbers.

Some carrier-specific services have used area code 700. In Canada, area code 600 is used for non-geographic applications. Area code 900 has been used for high-toll 900 numbers.

Cellular mobile services[edit]

The North American Numbering Plan does not set aside special non-geographic area codes exclusively for cellular phones, as is customary in some other national telephone administrations. Only one regional exception exists in area code 600 in Canada.

For cellular services, telephone numbers in the NANP are allocated within each area code from special central office prefixes. Calls to them are billed at the same rate as any other call. Consequently, the caller pays pricing model adopted in other countries, in which calls to cellular phones are charged at a higher nationwide rate, but incoming mobile calls are not charged to the mobile user, could not be implemented. Instead, North American cellular telephone subscribers are also generally charged for receiving calls (subscriber pays). In the past, this has discouraged mobile users from publishing mobile telephone numbers, but by the first decade of the 21st century, most users selected bundle pricing plans that included an allotment of minutes expected to be used in the billing period, and most U.S. carriers now offer unlimited calling plans at mass-market prices.[39]

Industry observers have attributed the relatively low mobile phone penetration rate in the United States, compared to that of Europe, to the subscriber-pays model.[citation needed] In this model the convenience of the mobility is charged to the subscriber. Callers from outside the local-calling region of the assigned number, however, pay for a long-distance call, although domestic long-distance rates are generally lower than the rates in caller-pays systems. Conversely, an advantage of caller-pays is the relative absence of telemarketing and nuisance calls to mobile numbers. The integrated numbering plan also enables local number portability between fixed and wireless services within a region, allowing users to switch to mobile service while keeping their telephone number.

The initial plan for area code overlays did allow for providing separate area codes for use by mobile devices, although these were still assigned to a specific geographical area, and were charged at the same rate as other area codes. Initially, the area code 917 for New York City was specifically assigned for this purpose within the boroughs; however, a Federal court overturned the practice and the use of an area code for a specific telephony purpose.[citation needed] Since mobile telephony has been expanding faster than landline use, new area codes typically have a disproportionately large fraction of mobile and nomadic numbers, although landline and other services rapidly follow and local network portability can blur these distinctions.

Growth[edit]

Canada and the United States have experienced rapid growth in the number of area codes, particularly between 1990 and 2005. The widespread adoption of fax, modem, and mobile phone communication, as well as the deregulation of local telecommunication services in the United States in the mid-1990s, increased the demand for telephone numbers.

The Federal Communications Commission allowed telecommunication companies to compete with the incumbent local exchange carriers for services, usually by forcing the existing sole service provider to lease infrastructure to other local providers. Because of the original design of the numbering plan and the telephone switching network that assumed only a single provider, number allocations had to be made in 10,000-number blocks even when far fewer numbers were required for each new vendor. Due to the proliferation of service providers in some numbering plan areas, many area codes fell into jeopardy, facing exhaustion of numbering resources. The number blocks of failed service providers often remained unused, as no regulatory mechanism existed to reclaim and reassign these numbers.

Area codes are added by two principal methods, number plan area splits and overlays. Splits were implemented by dividing an area into two or more regions, one of which retained the existing area code and the other areas receiving a new code. In an overlay, multiple codes are assigned to the same geographical area, obviating the need for renumbering of existing services. Subtle variations of these techniques have been used as well, such as dedicated overlays, in which the new code is reserved for a particular type of service, such as cellular phones and pagers, and concentrated overlays, in which a part of the area retained a single code while the rest of the region received an overlay code. The only service-specific overlay in the NANP was area code 917 (New York City) when it was first installed; such service-specific area code assignments were later prohibited by the Federal Communications Commission.

Most area codes of the form N10, originally reserved for AT&T’s Teletypewriter eXchange (TWX) service, were transferred to Western Union in 1969 and were freed up for other use in 1981 after conversion to Telex II service was complete. The last of these, 610, was assigned to Canada, but reassigned in 1992. These new area codes, as well as a few other codes used for routing calls to Mexico, were used for telephone area code splits in the late 1980s and early 1990s, as all other area codes under the original plan had been consumed.

After the remaining valid area codes were used up by expansion, in 1995 the rapid increase in the need for more area codes forced the NANPA to allow the digits 2 through 8 to be used as a middle digit in new area code assignments, with 9 being reserved as a last resort for potential future expansion. At the same time, local exchanges were allowed to use 1 or 0 as a middle digit. The first area codes without a 1 or 0 as the middle digit were area code 334 in Alabama and area code 360 in Washington, which both began service on January 15, 1995. This was quickly followed by area code 520 serving Arizona on March 19, 1995.

By 1995, many cities in the United States and Canada had more than one area code, either from dividing a city into different areas (NPA split) or having more than one code for the same area (NPA overlay). The overlay method requires that the area code must be dialed in all cases, even for local calls, while the split plan may permit seven-digit dialing within the same area. The transition to ten-digit dialing typically starts with a permissive dialing phase, which is widely publicized, during which dialing all ten digits is optional. After a period of several months, mandatory dialing begins, when seven-digit dialing is no longer permissible. Atlanta was the first U.S. city to require mandatory ten-digit dialing throughout the metropolitan area, roughly coinciding with the 1996 Summer Olympics held there. Atlanta was used as the test case not only because of its size, but also because it had the world’s largest fiber-optic network at the time, five times larger than that of New York, and it was home to BellSouth (now part of AT&T), then the Southeastern Regional Bell Operating Company, with AT&T’s fiber optics manufacturing facility within the city.

Growth problems[edit]

Depending on the techniques used for area code and central office code relief, the effect on telephone users varies. In areas in which overlays were used, this generally avoids the need for converting telephone numbers, so existing directories, business records, letterheads, business cards, advertising, and «speed-dialing» settings can retain the same phone numbers, while the overlay is used for new number allocations. The primary effect on telephone users is the necessity of remembering and dialing 10- or 11-digit numbers when only 7-digit dialing was previously permissible.

Splitting instead of overlaying generally avoids the requirement for mandatory area-code dialing within the new regions, but at the expense of having to convert a region to the new code, which necessitates updating records and directories to accommodate the new numbers. A smooth adjustment to splitting requires a period of «permissive dialing» during which the new and old codes are both allowed to work. Also, many splittings involved significant technical issues, especially when the area splittings occurred over boundaries other than phone network divisions.

As an example, in 1998, the area code 612, assigned to the Minneapolis – Saint Paul Twin Cities, was split to create a new area code 651 for St. Paul and the eastern metropolitan area. The Minnesota Public Utilities Commission mandated that the new boundary exactly follow municipal boundaries, which were distinctly different from telephone exchange boundaries, and that all subscribers keep their seven-digit numbers. These two goals were directly at odds with the reason for the split, namely to provide additional telephone numbers. More than forty exchanges had territory that straddled the new boundary. As a result, prefixes were duplicated in both area codes, which counteracted much of the benefit of the split, with only 200 of 700 prefixes in area 612 moving entirely to area 651. In less than two years, area code 612 again exhausted its supply of telephone numbers, and necessitated a three-way split in 2000, creating the new area codes 763 and 952. The split again followed political boundaries, rather than rate center boundaries, resulting in additional split prefixes; a few numbers moved from 612 to 651 to 763 in less than two years.

Decrease of growth rate[edit]

Recognizing that the proliferation of area codes was largely due to the telecom deregulation act and the assignment of numbers in blocks of ten thousand, the FCC instructed NANPA, by then administered by Neustar, to alleviate the numbering shortage. As a result, number pooling was piloted in 2001 as a system for allocating local numbers to carriers in blocks of 1,000 rather than 10,000. Because of the then design of the switched telephone network, this was a considerable technical obstacle. Number pooling was implemented with another technical obstacle, local number portability.

The program has been implemented in much of the United States by state regulators. Some cities have also implemented rate center consolidation; fewer rate centers resulted in more efficient use of telephone numbers, as carriers would reserve blocks of 1,000 or 10,000 numbers in each of multiple rate centers in the same area even if they had relatively few clients in the area.[40] (A rate center is a geographical area used by a Local Exchange Carrier (LEC) to determine the boundaries for local calling, billing and assigning phone numbers. Typically a call within a rate center is local, while a call from one rate center to another is a long-distance call.) Together with aggressive reclamation of unused number blocks from telecom providers, number pooling has reduced the need for additional area codes, so that many previously designated area splits and overlays have been postponed indefinitely.

Canada never implemented number pooling, so that even the smallest villages are rate centers and every CLEC is assigned blocks of ten thousand numbers.

New area codes outside the contiguous United States and Canada[edit]

Before 1995, all NANP countries and territories outside the contiguous United States, Alaska, Hawaii and Canada shared the area code 809. This included Puerto Rico and the U.S. Virgin Islands. Each has since been assigned one or more distinct numbering plan areas; area code 809 now exclusively serves the Dominican Republic (along with area codes 829 and 849). The United States Pacific territories of the Northern Mariana Islands and Guam joined the NANP in 1997, and American Samoa became an NANP member in October 2004. The Dutch possession of Sint Maarten was originally scheduled to join the NANP on May 31, 2010, but the changeover was postponed to September 30, 2011.[13]

Bermuda before 1995: served by area code 809 1995: assigned area code 441
Puerto Rico before 1996: served by area code 809 1996: assigned area code 787

2001: overlaid with area code 939

U.S. Virgin Islands before 1997: served by area code 809 1997: assigned area code 340
Northern Marianas before 1997: reached via IDDD using country code 670 1997: assigned area code 670
Guam before 1997: reached via IDDD using country code 671 1997: assigned area code 671
American Samoa before October 1, 2004: reached via IDDD using country code 684 2004: assigned area code 684
Sint Maarten before September 30, 2011: reached via IDDD using country code 599 2011: assigned area code 721

Telephone number size expansion[edit]

The NANP exhaust analysis estimates that the existing numbering system is sufficient beyond 2049, based on the assumptions that a maximum of 674 NPAs continue to be available, and that on average 3,990 central office codes are needed per year.[41]

In case of exhaustion, various plans are discussed for expanding the numbering plan. One option is to add the digit 1 or 0 either at the beginning or at the end of the area code, or prefixing it to the seven-digit subscriber number. This would require eleven-digit dialing even for local calls between any two NANP numbers. Another proposal introduces the digit 9 into the area code in the format x9xx, so that, for example, San Francisco’s 415 would become 4915. Other proposals include reallocating blocks of numbers assigned to smaller long-distance carriers or unused reserved services.[citation needed]

Dialing procedures[edit]

The structure of the North American Numbering Plan permits implementation of local dial plans in each plan area, depending on requirements. When multiple NPA codes serve an area in an overlay arrangement, ten-digit (10D) dialing is required. Seven-digit (7D) dialing may be permissible in areas with single area codes.[42] Depending on the requirement of toll alerting, it may be necessary to prefix a telephone number with 1. The NANPA publishes dial plan information for individual area codes.[43]

The standard dial plans in most cases are as follows:

Local within area code Local outside area code Toll within area code Toll outside area code
Single code area, with toll alerting 7D or 10D 7D or 10D 1+10D 1+10D
Single code area, without toll alerting 7D or 10D 1+10D 7D or 10D 1+10D
Overlaid area, with toll alerting 10D 10D 1+10D 1+10D
Overlaid area, without toll alerting 10D 1+10D 10D 1+10D

The number of digits dialed is unrelated to being a local call or a toll call when there is no toll alerting. Allowing 7D local dial across an area code boundary, which is uncommon today, requires central office code protection, locally if using toll alerting, across the entire area code otherwise, to avoid assignment of the same seven-digit number on both sides. Landlines occasionally require 1+10D where 10D is required, most notably in California.

Most areas permit local calls as 1+10D except for Texas, Georgia, and some jurisdictions in Canada which require that landline callers know which numbers are local and which are toll, dialing 10D for local calls and 1+10D for all toll calls.

In almost all cases, domestic operator-assisted calls are dialed 0+10D.

Special numbers and codes[edit]

Some common special numbers in the North American system:

  • 0 — operator assistance
  • 00 — long-distance operator assistance (formerly 2-1-1)
  • 011 — international access code using direct dial (for all destinations outside the NANP)
  • 01 — international access code using operator assistance (for all destinations outside the NANP)
  • 101-xxxx — used to select use of an alternative long-distance carrier
  • 211 — local community information or social services (in some cities)
  • 311 — city government or non-emergency police matters
  • 411 — local telephone directory service (Some telephone companies provide national directory assistance)
  • 511 — traffic, road, and tourist information
  • 611 — telephone line repair service (formerly 4104), wireless operator customer service (formerly 811)
  • 711 — relay service for customers with hearing or speech disabilities
  • 811 — local utility location services (United States), non-urgent telehealth/teletriage services in Canada (formerly telephone company business office)
  • 911 — emergency telephone number — fire department, medical emergency, police
  • 988 — National Suicide Prevention Lifeline (United States)[44]
  • 950-xxxx — Feature group code for access to a carrier from a non-subscriber location. The feature requires the customer dial a 950-xxxx number and enter a calling card number and destination telephone number. It was originally used for locations where 101-xxxx dialing was not possible.
  • 958-xxxx (local); 959-xxxx (long distance) — Plant test numbers, such as automatic number announcement circuits. It was once common to reserve entire unused exchange prefixes or N11 numbers (4101 was ringback number on many step-by-step switches), but these have largely moved to individual unpublished numbers within the standard 958-xxxx (local) or 959-xxxx (long-distance) plant test exchanges as numbers become scarce.
  • 1 (NPA) 555-1212 — non-local directory information (Canada and United States)

Vertical service codes are used for special calling features, such as:

  • *51 and 1151 — a history of unanswered calls on a telephone number, useful for those who are not Caller ID subscribers
  • *57 and 1157 — used to trace harassing, threatening, abusive, obscene, etc. phone calls, and keep results of trace at phone company
  • *66 and 1166 — to keep retrying a busy-line (see also Called-party camp-on)
  • *67 and 1167 — Caller ID Block
  • *69 and 1169 — Call Return (caller may press ‘1’ to return call after hearing number)
  • *70 and 1170 — cancel call waiting on a call-by-call basis
  • *71 and 1171 — three-way calling, which lets a person talk to people in two different locations at the same time
  • *74 and 1174 — speed dial, which allows someone to quickly dial any of eight frequently called numbers using a one-digit code, from any phone on their line
  • *75 — allows a total of 30 speed-call numbers with two digits
  • *77 — activates Anonymous Call Rejection Service
  • *82 and 1182 — releases Caller ID block on a call-by-call basis
  • *87 — deactivates Anonymous Call Rejection Service

The four-digit numbers are not implemented in some areas. The star codes (*) are for use on Touch-Tone telephones, whereas the four-digit numbers prefixed 11xx are used on rotary dial telephones which cannot dial the * symbol.

Not all NANP countries use the same codes. For example, the emergency telephone number is not always 911: Trinidad and Tobago and Dominica use 999, as in the United Kingdom. The country of Barbados uses 211 for police force, 311 for fire, and 511 for ambulance, while Jamaica uses 114 for directory assistance, 119 for police force, and 110 for fire and ambulance services.

Despite its early importance as a share of the worldwide telephone system, few of the NANP’s codes, such as 911, have been adopted outside the system. Determining that 911 requires unnecessary rotation time on rotary dial telephones, the European Union has adopted its own standardized number of 112, while countries in Asia and the rest of the world use a variety of other two- or three-digit emergency telephone number combinations. The 112 code is gaining prevalence because of its preprogrammed presence in mobile telephones that conform to the European GSM standard. The European Union and many other countries have chosen the International Telecommunication Union’s 00 as their international access number instead of 011. However, the toll-free prefix 800 has been widely adopted elsewhere, including as the international toll-free country code. It is often preceded by a 0 rather than a 1 in many countries where 0 is the trunk prefix.

International dialing[edit]

While international direct dialing was available in some locations in the United States by the late 1950s, a continental system was introduced as
International Direct Distance Dialing (IDDD) for the territories of the North American Numbering Plan in March 1970.[45]

While the NANP was designed as a closed numbering plan with ten digit telephone numbers, IDDD was implemented through extensive modifications in the switching systems to accommodate the international open numbering plan with seven to twelve digits in the national telephone numbers.[46] Access to the international network is facilitated by the dialing prefix 011, after which the country calling code and the national telephone number are dialed.

Number portability[edit]

The Telecommunications Act of 1996 (47 U.S.C. § 251 (b)(2)) authorizes the Federal Communications Commission (FCC) to require all local exchange carriers (LECs) to offer local number portability.[47] The FCC regulations were enacted on June 27, 1996, with changes to take effect in the one hundred largest Metropolitan Statistical Areas by October 1, 1997, and elsewhere by December 31, 1998.[48]

The FCC directed the North American Numbering Council (NANC) to select one or more private-sector candidates for the local number portability administrator (LNPA) function,[49] in a manner akin to the selection of the North American Numbering Plan Administrator (NANPA).[50]

The toll-free telephone numbers in NPA 800, 888, 877, 866, 855, 844, and 833 have been portable through the RespOrg system since 1993.[51]

Toll charges[edit]

Telephone calls between countries and territories of the NANP are not typically charged at domestic rates. For example, most long-distance plans may charge a California subscriber a higher rate for a call to British Columbia than for a call to New York, even though both destinations are within the NANP. Similarly, calls from Bermuda to U.S. destinations incur international rates. Even toll-free numbers may incur charges to callers. This is because many of the island nations implemented a plan of subsidizing the cost of local telephone services by directly charging higher pricing levies on international long-distance services.[citation needed]

Because of these higher fees, scams had taken advantage of customers’ unfamiliarity with pricing structure to call the legacy regional area code 809. Some scams lured customers from the United States and Canada into placing expensive calls to the Caribbean, by representing area code 809 as a regular domestic, low-cost, or toll-free call. The split of 809 (which formerly served all of the Caribbean NANP points) into multiple new area codes created many new, unfamiliar prefixes which could be mistaken for U.S. or Canada domestic area codes but carried high tariffs. In various island nations, premium exchanges such as +1-876-HOT-, +1-876-WET- or +1-876-SEX- (where 876 is Jamaica) became a means to circumvent consumer-protection laws governing area code 900 or similar U.S.-domestic premium numbers.

The occurrence of these scams has been on the decline, with many of the Cable and Wireless service monopolies being opened up to competition, hence lowering rates. Additionally, many Caribbean territories have implemented local government agencies to regulate telecommunications rates of providers.[52][53]

Countries and territories[edit]

Of all states or territories, the U.S. state of California has the largest number of area codes assigned, followed by Texas, Florida and New York, while most countries of the Caribbean use only one.[54] Many Caribbean codes were assigned based on alphabetic abbreviations of the territory name, as indicated in the third column of the following table (Letter code). This follows the traditional letter assignments on telephone dials. For some Pacific islands, the NANPA area code is the same as the country code that was discontinued upon membership in the NANP.

Country/Territory Area codes Letter code Regulator
 American Samoa 684* American Samoa Telecommunications Authority
 Anguilla 264 ANG Public Utilities Commission of Anguilla
 Antigua and Barbuda 268 ANT Telecommunications Division of the Government of Antigua and Barbuda
 Bahamas 242 BHA Utilities Regulation & Competition Authority
 Barbados 246 BIM Telecommunications Unit
 Bermuda 441 https://www.ra.bm/
 British Virgin Islands 284 BVI Telecommunications Regulatory Commission
Canada Canada 204, 226, … 905 Canadian Numbering Administration Consortium
 Cayman Islands 345 Information and Communications Technology Authority
 Dominica 767 ROS (Roseau) Eastern Caribbean Telecommunications Authority
 Dominican Republic 809, 829, 849 Instituto Dominicano de las Telecomunicaciones
 Grenada 473 GRE Eastern Caribbean Telecommunications Authority
 Guam 671* Guam Telephone Authority
 Jamaica 876, 658[55] Spectrum Management Authority
 Montserrat 664 Montserrat Info-Communications Authority
 Northern Mariana Islands 670*
 Puerto Rico 787, 939 PUR Junta Reglamentadora de Telecomunicaciones de Puerto Rico
 Saint Kitts and Nevis 869 National Telecommunications Regulatory Commission
 Saint Lucia 758 SLU National Telecommunications Regulatory Commission
 Saint Vincent and the Grenadines 784 SVG National Telecommunications Regulatory Commission
 Sint Maarten[13] 721 Bureau Telecommunications and Post
 Trinidad and Tobago 868 TNT Telecommunications Authority of Trinidad and Tobago
 Turks and Caicos Islands 649 Telecommunications Commission
 United States 201, 202, … 989 Federal Communications Commission
 United States Virgin Islands 340 Public Services Commission
* same as previous country code

Membership in the NANP brings significant advantages for countries in the vicinity of the United States and Canada, which usually are already the top dialing destinations. Both countries also originate most of the tourism business for the Caribbean. This is enhanced by the integration from sharing the same dialing procedures, without international access codes, and the toll-free number system of the NANP, as businesses in all member countries are eligible to participate.

Alphabetic mnemonic system[edit]

digit letters

Letters of the alphabet are mapped to the digits of the telephone dial pad.

2 ABC
3 DEF
4 GHI
5 JKL
6 MNO
7 P(Q)RS
8 TUV
9 WXY(Z)

Many telephone dials and keypads maintain a tradition of alphabetic dialing. Usually each pushbutton from digit 2 to 9 also displays three letters, which is standardized in ISO 9995-8 and, in Europe, E.161. Historically, the letters Q and Z were omitted, although some modern telephones contain them. SMS-capable devices have all 26 letters. The alphabet is apportioned to the buttons as follows:

No letters are typically mapped to keys 1 and 0, although some corporate voicemail systems use 1 for Q and Z, and some old telephones assigned the Z to the digit 0.

Originally, this scheme was used as a mnemonic device for the exchange prefixes in telephone numbers. When telephone numbers in the United States were standardized in the mid-20th century to seven digits, the first two digits of the exchange prefix were expressed as letters rather than numbers, using the telephone exchange name. Before World War II, the largest cities used three letters and four or five numerals, while in most cities phone numbers had only six digits (2L-4N). The prefix was a name and the first two or three letters, listed as capital letters in directories, were dialed. Later, the third letter, where implemented, was replaced by a digit, or an extra digit was added. This generally happened after World War II, although New York City converted in 1930. The adoption of seven-digit local numbers (2L-5N) was chosen as the requirement for direct distance dialing and progressively deployed starting in the late 1940s.

The famous Glenn Miller tune PEnnsylvania 6-5000 refers to telephone number PE6-5000, a number in service at the Hotel Pennsylvania (212 736-5000) in New York up until 2020 when the hotel closed permanently. Similarly, the classic film BUtterfield 8 is set in the East Side of Manhattan between roughly 64th and 86th Streets, where the telephone prefixes include 288.

The letter system was phased out, beginning before 1965, although it persisted ten years later in some places. It was included in Bell of Pennsylvania directories until 1983. Even today, some businesses still display a 2L-5N number in advertisements, e.g., the Belvedere Construction Company in Detroit, Michigan not only still uses the 2L-5N format for its number (TYler 8-7100), it uses the format for the toll-free number (1-800-TY8-7100).

Despite the phasing out of the letter system, alphabetic phonewords remain as a commercial mnemonic gimmick, particularly for toll-free numbers. For example, one can dial 1-800-FLOWERS to order flowers, or 1-800-DENTIST to find a local dentist.

In addition to commercial uses, alphabetic dialing has occasionally influenced the choice of area codes. For example, when area code 423 (East Tennessee) was split in 1999, the region surrounding Knoxville was assigned area code 865, chosen to represent VOL, for The Volunteer State, the nickname of Tennessee, as well as athletic teams at the University of Tennessee.[56][57] Similarly, several Caribbean area codes were chosen as an alphabetic abbreviation of the country name.

Fictional telephone numbers[edit]

American television programs and films often use the central office code 555, or KLamath 5 and KLondike 5 in older movies and shows, for fictitious telephone numbers, to prevent disturbing actual telephone subscribers if anyone is tempted to dial a telephone number seen or referred to on screen. Not all numbers beginning with 555 are fictional. For example, 555-1212 is the standard number for directory assistance. Only 555-0100 through 555-0199 are reserved for fictional use. Where used, these are often routed to information services; Canadian telephone companies briefly promoted 555-1313 as a pay-per-use «name that number» reverse lookup in the mid-1990s.[58]

Occasionally, valid telephone numbers are used as song titles. The 1962 Motown hit «Beechwood 4-5789» was written by Marvin Gaye for the Marvelettes, while Stax/Volt Records’ Wilson Pickett scored a soul hit in the 1960s with the similarly named «634-5789». A more recent example is the 1981 song «867-5309/Jenny» by Tommy Tutone, which was the cause of a large number of prank calls.[59]

Telephone number formatting[edit]

NANP telephone numbers are usually written as NPA-NXX-XXXX or (NPA) NXX-XXXX . For example, 250 555 0199, a fictional number, could be written as 250-555-0199, (250) 555-0199, 250-5550199, or 250/555-0199. The Government of Canada’s Translation Bureau recommends using hyphens between groups; e.g. 250-555-0199.[60]

Using the global formatting for telephone numbers, per recommendation E.164 by the International Telecommunication Union (ITU), a NANP number is written as +1NPANXXXXXX, without spaces or punctuation, e.g. +12505550199.

See also[edit]

  • List of area code overlays
  • List of North American Numbering Plan area codes
  • Numbering Resource Utilization/Forecast Report

References[edit]

  1. ^ «Contacts in the Countries Participating in the North American Numbering Plan» (PDF).
  2. ^ «Canadian Numbering Administrator».
  3. ^ «NANPA : Number Resources — NPA (Area) Codes». Retrieved 2015-10-23.
  4. ^ ITU; ITU-T. «The International Public Telecommunication Numbering Plan». ITU. Retrieved 2015-07-25.
  5. ^ Nunn, W. H. (1952). «Nationwide Numbering Plan». Bell System Technical Journal. 31 (5): 851–9. doi:10.1002/j.1538-7305.1952.tb01412.x.
  6. ^ «1951: First Direct-Dial Transcontinental Telephone Call». AT&T Corporation. Retrieved 2007-06-08.
  7. ^ a b c AT&T, Notes on Distance Dialing (1968).
  8. ^ AT&T, Notes on Distance Dialing (1975).
  9. ^ «NANPA: North American Numbering Plan Administration — About Us».
  10. ^ Mehta, Stephanie N. (1999-02-26). «The Kennedy Space Center Acquires A New Area Code: 3-2-1, as in Blast Off». The Wall Street Journal.
  11. ^ AT&T, Notes on the Network, Section 3, p.8 (1980)
  12. ^ Green book, Volume 2, Part 1, International Telegraph and Telephone Consultative Committee, International Telecommunication Union, 1973, page 129
  13. ^ a b c «PL-418: Introduction of NPA 721 (Sint Maarten)» (PDF). North American Numbering Plan Administration. 2011-01-05. Retrieved 2011-08-08. Updated by: «PL-423: Updated Information — Introduction of NPA 721 (Sint Maarten)» (PDF). North American Numbering Plan Administration. 2011-07-27. Retrieved 2011-08-08.
  14. ^ «About the North American Numbering Plan».
  15. ^ Bellcore Planning Letter PL-NANP-106, (1997-12-23)
  16. ^ «About NANPA». Neustar. Retrieved 2015-06-23.
  17. ^ FCC News release: FCC selects Somos as NANPA and PA under one-year bridge contract.
  18. ^ «Somos, Inc. Is Awarded the North American Numbering Plan Administration and the Pooling Administration Contracts | Somos».
  19. ^ FCC awards $75M NANPA/PA/RNDA Services contract, G2Xchange FedCiv (2020-12-01), Retrieved 2021-05-04.
  20. ^ a b c d e AT&T (1955) Notes on Nationwide Dialing
  21. ^ a b Notes on the Network, AT&T (1980)
  22. ^ W.H. Nunn, Nationwide Numbering Plan, Bell System Technical Journal 31(5), 851 (1952)
  23. ^ AT&T, Notes on the Network, Section 10, p.3 (1980).
  24. ^ John Greene (2015-01-16). «Why Did Old Phone Numbers Start With Letters?». Mental Floss. Retrieved 2019-02-01.
  25. ^ Mabbs, Ralph (Winter 1947–1948). «Nation-Wide Operator Toll Dialing—the Coming Way». Bell Telephone Magazine. 26 (4): 181. Retrieved 2022-12-26.
  26. ^ «Now You Can Call, If Your Calls Don’t Work Some Business Lines Aren’t Set Up To Call To New Area Codes» Archived 2008-03-16 at the Wayback Machine, The Virginian-Pilot, November 1, 1995. Accessed June 8, 2007. «When the first area code, 201, was introduced in New Jersey in 1951, phone-numbering experts thought there would be enough codes with a middle digit of 0 or 1 to last well into the next century.»
  27. ^ Statistical Abstract of the United States. 1960. p. 516. Retrieved 2019-02-01.
  28. ^ Bell Telephone Laboratories, A History of Engineering and Science in the Bell System — The Early Years (1875-1925), M.D. Fagan (ed.), 1975, p.126
  29. ^ a b c Blair N.D., Cosgrove M.P. (AT&T), why all numbers?, Bell Telephone Magazine, Autumn 1962, p.10
  30. ^ Alliance for Telecommunications Industry Solutions (ATIS), Numbering and Dialing Plans within the United States (ATIS-0300076), December 2008, p.7
  31. ^ AT&T, All-Number Calling Being Introduced In Bell System, Bell Laboratories Record 38(12) p.470 (December 1960)
  32. ^ Bell Telephone Laboratories, Engineering and Operations in the Bell System (1984), p.119
  33. ^ «Numbering Resources: NPA (Area) Codes». NANP. Neustar. Archived from the original on 2013-01-04. Retrieved November 13, 2021.
  34. ^ «CNA — North American Numbering Plan».
  35. ^ «NANPA : North American Numbering Plan Administration — About Us».
  36. ^ «NANP North American Numbering Plan useful facts».
  37. ^ «NANP: The North American Numbering Plan Explained». 28 December 2020.
  38. ^ North American Numbering Plan Administrator, Planning Letter PL-558, 2021-01-28.
  39. ^ See, e.g., AT&T plans, T-Mobile Magenta plans, and Verizon unlimited plans.
  40. ^ Rate Center Consolidations
  41. ^ «April 2019 North American Numbering Plan (NANP) Exhaust Analysis» (PDF). Archived from the original (PDF) on 2020-02-19.
  42. ^ «Uniform Dialing Plans».
  43. ^ «Area Codes Requiring 10 Digit Dialing».
  44. ^ «FCC Designates 988 for the National Suicide Prevention Lifeline». Federal Communications Commission. 2020-07-16. Retrieved 2021-12-06.
  45. ^ AT&T, Notes on Distance Dialing (1975)
  46. ^ AT&T, Notes on the Network, Section 10.3.02, p.3 (1980).
  47. ^ 11 FCC Rcd 8353
  48. ^ 11 FCC Rcd 8355. The regulations are located at 47 CFR 52, 47 CFR 52.20 et seq.
  49. ^ 47 CFR 1.1204
  50. ^ 11 FCC Rcd 8401
  51. ^ 10 FCC Rcd 12351
  52. ^ Administrator. «Fair Trading Commission, Barbados — Legislation».
  53. ^ «The Eastern Caribbean Telecommunications Authority (ECTEL) > Telecom regulations». Archived from the original on 2011-07-18. Retrieved 2009-03-13.
  54. ^ «United States Area Codes». www.areacodehelp.com. Retrieved 2018-09-27.
  55. ^ «Call 658 … Jamaica gets additional area code, 10-digit dialling becomes mandatory May 2018». 28 August 2017.
  56. ^ Brewer, Bill. 423 Area Code To Become VOL In 9 ET Counties. Knoxville News-Sentinel. April 17, 1999.
  57. ^ Tennessee Regulatory Authority press release, April 29, 1999
  58. ^ «Canadian telco offers users a handy reverse directory». America’s Network. 1996-05-15.
  59. ^ «867-5309/Jenny». Urban Legends Reference Pages. snopes.com. 2014-07-09. Retrieved 2017-06-28.
  60. ^ Government of Canada, Public Services and Procurement Canada (2019-12-06). «To Drop or Not to Drop Parentheses in Telephone Numbers – Favourite Articles – Writing Tools – Resources of the Language Portal of Canada – Languages – Canadian identity and society – Culture, history and sport – Canada.ca». www.noslangues-ourlanguages.gc.ca. Retrieved 2022-02-10.

External links[edit]

  • North American Numbering Plan Administrator (NANPA)
  • Canadian Numbering Administrator
  • Map of the original 86 area codes from 1947
  • North American Numbering Council Archived 2022-01-20 at the Wayback Machine
  • NANP Discussion 2003 Document — Understanding the North American Numbering Plan
NANP countries.svg

Countries participating in the NANP

Format +1 NXX NXX-XXXX
Access codes
Country calling code 1
International call prefix 011
List of dialing codes

The North American Numbering Plan (NANP) is a telephone numbering plan for twenty-five regions in twenty countries, primarily in North America and the Caribbean. This group is historically known as World Zone 1 and has the international calling code 1. Some North American countries, most notably Mexico, do not participate in the NANP.

The concepts underlying the NANP were originally devised in the 1940s by the American Telephone and Telegraph Company (AT&T) for the Bell System and the independent telephone operators in North America. The goal was to unify the diverse local numbering plans that had been established in the preceding decades, speed call completion times, and reduce costs for toll calls, by reducing or eliminating manual labor by telephone operators, and eventually prepare the continent for direct-dialing of long-distance calls by customers. Direct dialing became possible in 1951 in a first trial, and was expanded across the nation in the decade following. AT&T continued to administer the numbering plan and the technical infrastructure until the breakup of the Bell System, when administration was delegated to the North American Numbering Plan Administrator (NANPA), a service that has been procured from the private sector by the Federal Communications Commission (FCC) in the United States. Each participating country forms a regulatory authority that has plenary control over local numbering resources.[1] The FCC also serves as the U.S. regulator. Canadian numbering decisions are made by the Canadian Numbering Administration Consortium.[2]

The NANP divides the territories of its members into numbering plan areas (NPAs) which are encoded numerically with a three-digit telephone number prefix, commonly called the area code.[3] Each telephone is assigned a seven-digit telephone number unique only within its respective numbering plan area. The telephone number consists of a three-digit central office (or exchange) code and a four-digit station number. The combination of an area code and the telephone number serves as a destination routing address in the public switched telephone network (PSTN). The North American Numbering Plan conforms with International Telecommunication Union (ITU) Recommendation E.164, which establishes an international numbering framework.[4]

History[edit]

Area code handbook issued by many telephone companies in 1962 to promote the newly introduced direct distance dialing

From the Bell System’s beginnings in 1876 and throughout the first part of the 20th century, telephone networks grew from essentially local or regional telephone systems. These systems expanded by growing their subscriber bases, as well as increasing their service areas by implementing additional local exchanges that were interconnected with tie trunks. It was the responsibility of each local administration to devise telephone numbering plans that accommodated the local requirements and growth.[5] As a result, the North American telephone service industry developed into an unorganized set of many differing local numbering systems. The diversity impeded the efficient operation and interconnection of exchanges into a nationwide system for long-distance telephone communication. By the 1940s, the Bell System set out to unify the various existing numbering plans to provide a unified, systematic approach for routing telephone calls across the nation and to provide efficient long-distance service that eventually did not require the involvement of switchboard operators.

In October 1947, AT&T published a new nationwide numbering plan in coordination with the independent telephone operators. The plan divided most of North America into eighty-six numbering plan areas (NPAs). Each NPA was assigned a unique three-digit code, typically called NPA code or simply area code. These codes were first used in Operator Toll Dialing by long-distance operators in establishing calls via trunks between toll offices. The goal of automatic service required additional technical advancements in the latest generation of toll-switching systems, completed by the early 1950s, and installation of new toll-switching systems in most numbering plan areas. The first customer-dialed direct call using an area code was made on November 10, 1951, from Englewood, New Jersey, to Alameda, California.[6] Direct distance dialing (DDD) was subsequently introduced across the country. By the early 1960s, DDD had become commonplace in cities and most towns in the United States and Canada. By 1967, the number of assigned area codes had grown to 129.[7]

The status of the network of the 1960s was reflected in a new name used in technical documentation: North American Integrated Network.[7] By 1975, the numbering plan was referred to as the North American Numbering Plan,[8] leading to the well-known acronym NANP, as other countries sought or considered joining in the standardization.

Foreign expansion[edit]

Although Bermuda and the Caribbean islands had been assigned the area code 809 as early as 1958 by the administrators at AT&T, individual participating countries or territories had no autonomy over their numbering plan as they received centrally assigned central office prefixes that needed to be unique from those of other countries with the same area code. Regions in Mexico with high call volumes to and from the US were assigned functional area codes as early as 1963, for the purpose of call routing, but a nationwide system of participation in the NANP eventually failed.

In the following decades, the NANP expanded to include all of the United States and its territories, Canada, Bermuda, and seventeen nations of the Caribbean.[9][10]

At the request of the British Colonial Office, the numbering plan was first expanded to Bermuda and the British West Indies because of their historic telecommunications administration through Canada as parts of the British Empire and their continued associations with Canada, especially during the years of the telegraph and the All Red Line system.

Not all North American polities participate in the NANP. Exceptions include Mexico, Greenland, Saint Pierre and Miquelon, the Central American countries and some Caribbean countries (Cuba, Haiti, the French Caribbean and the Dutch Caribbean, except for Sint Maarten). The only Spanish-speaking state in the system is the Dominican Republic. Mexican participation was planned,[11] but implementation stopped after three area codes (706, 903 and 905) had been assigned, and Mexico opted for an international numbering format, using country code 52.[12] The area codes in use were subsequently withdrawn in 1991.

The Dutch Caribbean territory of Sint Maarten joined the NANP in September 2011, receiving area code 721.[13] Sint Maarten shares the island with the French Collectivity of Saint Martin which, like the rest of the French Caribbean, is not part of the NANP.

Administration[edit]

The NANP is administered by the North American Numbering Plan Administrator (NANPA, formerly Administration).[14] This function is overseen by the Federal Communications Commission, which assumed the responsibility upon the breakup of the Bell System. The FCC solicits private sector contracts for the role of the administrator.

Before the breakup of the Bell System, administration of the North American Numbering Plan was performed by AT&T’s Central Services Organization. In 1984, this function was transferred to Bell Communications Research (Bellcore), a company created by the divestiture mandate to perform services for the newly created local exchange carriers. On January 19, 1998, the NANPA function was transferred to the IMS division of Lockheed Martin in Washington, D.C.[15] In 1999, the contract was awarded to Neustar, a company spun off from Lockheed for this purpose. The contract was renewed in 2004, and again in 2012.[16] On January 1, 2019, Somos assumed the NANPA function under a one-year bridge contract granted by the FCC with the goal of consolidating the NANPA function with the Pooling Administrator and identifying a long-term contract holder.[17][18] On December 1, 2020, Somos secured the $76 million contract for a term of eight years against one other bidder.[19]

Numbering plan[edit]

The vision and goal of the architects of the North American Numbering Plan was a system by which telephone subscribers in the United States and Canada could themselves dial and establish a telephone call to any other subscriber without the assistance of switchboard operators. While this required an expansion of most existing local numbering plans, many of which required only four or five digits to be dialed, or even fewer in small communities, the plan was designed to enable local telephone companies to make as few changes as possible in their systems.

Numbering plan areas and central offices[edit]

The new numbering plan divided the North American continent into regional service areas, called numbering plan areas (NPAs). The divisions primarily followed the jurisdictional boundaries of the U.S. states and the Canadian provinces.[20] Some states or provinces needed to be divided into multiple areas. NPAs were created in accordance with principles deemed to maximize customer understanding and minimize dialing effort, while reducing plant cost.[21] Each NPA was identified by a unique three-digit code number that was prefixed to the local telephone number, when calling from one NPA to another. Within the same numbering plan area, dialing the area code was not necessary.

The telephone exchanges—in the Bell System they were officially called central offices—became local exchange points in the nationwide system. Each of them was also assigned a three-digit number unique within its NPA. The combination of NPA code and central office code served as a destination routing code for use by operators to reach any central office through the switching network.[20] Due to the numerical structure of the numbering system, each NPA was technically limited to 540 central offices.[21]

Although the limitation to 540 central offices required the most populous states to be divided into multiple NPAs, it was not the sole reason to subdivide a state. An important aspect was the existing infrastructure for call routing, which had developed in preceding decades independently of state boundaries. The rules of determining areas also attempted to avoid cutting across busy toll traffic routes, so that most toll traffic remained within an NPA, and outgoing traffic in one area would not be tributary to toll offices in an adjacent area.[22][20] As a result, New York state was initially divided into five areas, the most of any state. Illinois, Ohio, Pennsylvania, and Texas were assigned four NPAs each, and California, Iowa, and Michigan received three. Eight states and provinces were split into two NPAs.

Traditionally, central office switching systems were designed to serve up to ten thousand subscriber numbers. Thus, subscribers were assigned four-digit line or station numbers. This rounded out the total number of digits in a subscriber telephone number to ten: a three-digit area code, three-digit central office code, and four digits for each line. This fixed format defined the North American Numbering Plan as a closed numbering plan,[23] as opposed to developments in other countries where the number of digits was not fixed.

The closed numbering plan did not require the subscriber to dial all digits. When making a local call or a call within the same numbering plan area, the area code was omitted, resulting in seven-digit dialing. Ten-digit dialing was only necessary when placing foreign area calls to subscribers in another state or numbering plan area.[24] Exceptions existed for communities located on NPA boundaries, so that uniform local dialing was still possible in historically established communities.

Initial numbering system[edit]

In 1947, AT&T completed the new design for a nationwide toll network that established the original North American area codes. The new organization provided for 152 area codes, each with a capacity to serve up to 540 central offices.[25] Originally, only eighty-six area codes were assigned. New Jersey received the first NPA code in the new system, area code 201.[26] The second area code, 202, was assigned to the District of Columbia. The allocation of area codes was readjusted as early as 1948 to account for inadequacies in some metropolitan areas. For example, the Indiana numbering plan area 317 was divided to provide a larger numbering pool in the Indiana suburbs of Chicago (area code 219).

Initially, states divided into multiple numbering plan areas were assigned area codes with the digit 1 in the second position, while areas that comprised entire states or provinces received codes with 0 as the middle digit. This rule was broken by the early 1950s,[20] as NPAs with digit 0 in the middle had to be split, but until 1995 all area codes assigned had none other than the digits 0 and 1 in this position.

The eight codes of the form N11 (N=2–9) were reserved as service codes. The easily recognizable codes of the form N00 were available in the numbering plan, but were not initially included in assignments.[7] Additional area code patterns were later assigned for other services; for example, the area codes N10 were implemented for the Teletypewriter Exchange Service (TWX).[27]

Central office codes[edit]

It was already common practice for decades that the digits 0 and 1 could not appear in the first two digits of the central office codes, because the system of using the first two letters of familiar names for central offices did not assign letters to these digits. The digit 0 was used for operator assistance, and 1, which is essentially a single pulse of loop interruption, was automatically ignored by most switching equipment of the time.[20] Therefore, the 0/1 rule for the area code provided a convenient means to distinguish seven-digit dialing from ten-digit dialing.

The use of telephone exchange names as part of telephone numbers had been a well-established practice, and this was preserved for convenience and expediency in the new network design. The letter-to-digit translations were printed on the face of every rotary dial in the metropolitan areas, according to a scheme designed by W.G. Blauvelt in 1917, that had been used in the Bell System in large metropolitan areas since the early 1920s.[28] The network reorganization standardized this system to using a two-letter, five-digit (2L-5N) representation of telephone numbers in most exchanges in North America,[29] or to using an equivalent all-numeric seven-digit numbering plans, as was practiced by some telephone companies.

All-number calling[edit]

Partitioning of the NANP prefix space
under all-number-calling
000 — 099 These 200 codes were used
as toll center and system codes.
100 — 199
area
codes
service
codes
area
codes
central office
codes
200 — 210 211 212 — 219 220 — 299
300 — 310 311 312 — 319 320 — 399
400 — 410 411 412 — 419 420 — 499
500 — 510 511 512 — 519 520 — 599
600 — 610 611 612 — 619 620 — 699
700 — 710 711 712 — 719 720 — 799
800 — 810 811 812 — 819 820 — 899
900 — 910 911 912 — 919 920 — 999
152 area codes
8 special service codes
640 CO codes

All-number calling was a telephone numbering plan introduced in 1958,[30] that converted telephone numbers with exchange names to a numeric representation of seven digits.

The original plan of 1947 had been projected to be usable beyond the year 2000. However, by the late 1950s it became apparent that it would be outgrown by about 1975.[31] The limitations for the usable leading digits of central office codes, imposed by using common names for central office names, and their leading two characters as guides for customer dialing could no longer be maintained when opening new central offices. By 1962 it was forecast that in 1985 the number of telephones in the nation would equal its population of 280 million and increase to 600 million telephones for 340 million people in 2000.[29] As a result, the North American telephone administrations first introduced letter combinations that could not be linked to a familiar pronounceable central office name. Finally, they sought the elimination of central office names and letter codes, and introduced all-number calling (ANC).

Under all-number calling, the number of permissible central office prefixes increased from 540 to potentially 800, but the first two digits of the central office code were still restricted to the range 2 to 9, and the eight combinations that ended in 11 were reserved as special calling codes.[29] This increased the numbering pool for central office codes to 640, and resulted in the partitioning of the prefix space (000999).[32]

Interchangeable central office codes[edit]

As the numbering plan grew in the 1960s under all-number calling, plan administrators at AT&T identified that by c. 1973 some of the largest area codes in urban centers might run out of central office prefixes to install more individual access lines. For relief in these cases, they finally removed the requirement that the middle digit of the central office code could not be 0 or 1. This resulted in the format of interchangeable central office codes, N X X, where N=2–9 and X=0–9. The first cities that required this action, in 1974, were the cities of Los Angeles with area code 213 and New York with 212. This change also required modification of the local dialing procedures to distinguish local calls from long-distance calls with area codes.

Requiring 1 to be dialed before the full number in some areas provided for area codes of the form N10, such as 210 in the San Antonio, Texas, area and 410 in eastern Maryland. Therefore, someone calling from San Jose, California, to Los Angeles before the change would have dialed 213-555-0123 and after the change 1-213-555-0123, which permitted the use of 213 as an exchange prefix in the San Jose area. The preceding 1 also ideally indicates a toll call; however, this is inconsistent across the NANP because the FCC has left it to the U.S. state public utilities commissions to regulate for traditional landlines, and it has since become moot for mobile phones and digital VoIP services that now offer nationwide calling without the extra digit.[citation needed]

Interchangeable NPA codes[edit]

In 1995, the North American Numbering Plan Administrator removed the requirement that the middle digit of an area code had to be either 0 or 1, implementing fully interchangeable NPA and central office codes, that had already been anticipated since the 1960s, when interchangeable central office codes were sanctioned.

Modern plan[edit]

The NANP numbering format may be summarized in the ten-digit notation NXX NXX-XXXX, where the Ns denote any of the digits 2–9, and the Xs denote any digit 0–9.

Component Name Number ranges Notes
NXX
often denoted NPA
Numbering plan area code The first NXX block is the numbering plan area code. When the second and third digits are the same, the code is an easily recognizable code (ERC). ERCs designate special services; e.g., 800 for toll-free service. The NANP is not assigning area codes with 9 as the second digit.[33] Covers Canada, the United States, parts of the Caribbean Sea, and some Atlantic and Pacific islands. The area code is often enclosed in parentheses.
NXX Central office code The second NXX block is the central office code. Permissible numbers exclude easily recognizable codes N11, used for special services. Also called exchange code
XXXX Line number A unique four-digit number for each NPA, from 0000 to 9999 Also called station code

Using 0 or 1 as the first digit of an area code or central office code is invalid, as is a 9 as the middle digit of an area code; these are trunk prefixes or reserved for North American Numbering Plan expansion.

For example, (234) 235-5678 is a valid telephone number; with area code 234, central office prefix (exchange) 235, and line number 5678. The number (234) 911-5678 is invalid, because the central office code must not be in the form N11. (314) 159-2653 is invalid, because the office code must not begin with 1. (123) 234-5678 is invalid, because the NPA must not begin with 0 or 1.[34][35][36][37]

Each three-digit area code has a capacity of 7,919,900 telephone numbers (7,918,900 in the United States).

Despite the widespread use of fictional telephone numbers of the form NXX 555-XXXX, only the block of line numbers from 0100 through 0199 are specifically reserved for this purpose, leaving the rest available for assignment.

The country calling code for all countries participating in the NANP is 1. The prefix 1 is also used with the NANP for long-distance dialing.

Non-geographic services[edit]

The North American Numbering Plan recognizes the need for non-geographic services by designating certain numbering blocks for such purposes. Many of these telephone numbers are selected from the easily recognizable codes (ERCs).

For system-wide toll-free calling, in which the receiving party is billed for the call, uses the number range with area codes of the form 8XX.

Area code and central office prefixes for other non-geographic services have the form 5XX-NXX. As of January 2021, the codes 500, 521, 522, 533, 544, 566, 577, 588, 523, 524, 525, and 526 have been designated.[38] These codes are used for fixed or mobile devices, and not assigned to rate centers. As addresses, they may or may not traverse the public switched telephone network (PSTN). Applications include the use as personal 500 numbers.

Some carrier-specific services have used area code 700. In Canada, area code 600 is used for non-geographic applications. Area code 900 has been used for high-toll 900 numbers.

Cellular mobile services[edit]

The North American Numbering Plan does not set aside special non-geographic area codes exclusively for cellular phones, as is customary in some other national telephone administrations. Only one regional exception exists in area code 600 in Canada.

For cellular services, telephone numbers in the NANP are allocated within each area code from special central office prefixes. Calls to them are billed at the same rate as any other call. Consequently, the caller pays pricing model adopted in other countries, in which calls to cellular phones are charged at a higher nationwide rate, but incoming mobile calls are not charged to the mobile user, could not be implemented. Instead, North American cellular telephone subscribers are also generally charged for receiving calls (subscriber pays). In the past, this has discouraged mobile users from publishing mobile telephone numbers, but by the first decade of the 21st century, most users selected bundle pricing plans that included an allotment of minutes expected to be used in the billing period, and most U.S. carriers now offer unlimited calling plans at mass-market prices.[39]

Industry observers have attributed the relatively low mobile phone penetration rate in the United States, compared to that of Europe, to the subscriber-pays model.[citation needed] In this model the convenience of the mobility is charged to the subscriber. Callers from outside the local-calling region of the assigned number, however, pay for a long-distance call, although domestic long-distance rates are generally lower than the rates in caller-pays systems. Conversely, an advantage of caller-pays is the relative absence of telemarketing and nuisance calls to mobile numbers. The integrated numbering plan also enables local number portability between fixed and wireless services within a region, allowing users to switch to mobile service while keeping their telephone number.

The initial plan for area code overlays did allow for providing separate area codes for use by mobile devices, although these were still assigned to a specific geographical area, and were charged at the same rate as other area codes. Initially, the area code 917 for New York City was specifically assigned for this purpose within the boroughs; however, a Federal court overturned the practice and the use of an area code for a specific telephony purpose.[citation needed] Since mobile telephony has been expanding faster than landline use, new area codes typically have a disproportionately large fraction of mobile and nomadic numbers, although landline and other services rapidly follow and local network portability can blur these distinctions.

Growth[edit]

Canada and the United States have experienced rapid growth in the number of area codes, particularly between 1990 and 2005. The widespread adoption of fax, modem, and mobile phone communication, as well as the deregulation of local telecommunication services in the United States in the mid-1990s, increased the demand for telephone numbers.

The Federal Communications Commission allowed telecommunication companies to compete with the incumbent local exchange carriers for services, usually by forcing the existing sole service provider to lease infrastructure to other local providers. Because of the original design of the numbering plan and the telephone switching network that assumed only a single provider, number allocations had to be made in 10,000-number blocks even when far fewer numbers were required for each new vendor. Due to the proliferation of service providers in some numbering plan areas, many area codes fell into jeopardy, facing exhaustion of numbering resources. The number blocks of failed service providers often remained unused, as no regulatory mechanism existed to reclaim and reassign these numbers.

Area codes are added by two principal methods, number plan area splits and overlays. Splits were implemented by dividing an area into two or more regions, one of which retained the existing area code and the other areas receiving a new code. In an overlay, multiple codes are assigned to the same geographical area, obviating the need for renumbering of existing services. Subtle variations of these techniques have been used as well, such as dedicated overlays, in which the new code is reserved for a particular type of service, such as cellular phones and pagers, and concentrated overlays, in which a part of the area retained a single code while the rest of the region received an overlay code. The only service-specific overlay in the NANP was area code 917 (New York City) when it was first installed; such service-specific area code assignments were later prohibited by the Federal Communications Commission.

Most area codes of the form N10, originally reserved for AT&T’s Teletypewriter eXchange (TWX) service, were transferred to Western Union in 1969 and were freed up for other use in 1981 after conversion to Telex II service was complete. The last of these, 610, was assigned to Canada, but reassigned in 1992. These new area codes, as well as a few other codes used for routing calls to Mexico, were used for telephone area code splits in the late 1980s and early 1990s, as all other area codes under the original plan had been consumed.

After the remaining valid area codes were used up by expansion, in 1995 the rapid increase in the need for more area codes forced the NANPA to allow the digits 2 through 8 to be used as a middle digit in new area code assignments, with 9 being reserved as a last resort for potential future expansion. At the same time, local exchanges were allowed to use 1 or 0 as a middle digit. The first area codes without a 1 or 0 as the middle digit were area code 334 in Alabama and area code 360 in Washington, which both began service on January 15, 1995. This was quickly followed by area code 520 serving Arizona on March 19, 1995.

By 1995, many cities in the United States and Canada had more than one area code, either from dividing a city into different areas (NPA split) or having more than one code for the same area (NPA overlay). The overlay method requires that the area code must be dialed in all cases, even for local calls, while the split plan may permit seven-digit dialing within the same area. The transition to ten-digit dialing typically starts with a permissive dialing phase, which is widely publicized, during which dialing all ten digits is optional. After a period of several months, mandatory dialing begins, when seven-digit dialing is no longer permissible. Atlanta was the first U.S. city to require mandatory ten-digit dialing throughout the metropolitan area, roughly coinciding with the 1996 Summer Olympics held there. Atlanta was used as the test case not only because of its size, but also because it had the world’s largest fiber-optic network at the time, five times larger than that of New York, and it was home to BellSouth (now part of AT&T), then the Southeastern Regional Bell Operating Company, with AT&T’s fiber optics manufacturing facility within the city.

Growth problems[edit]

Depending on the techniques used for area code and central office code relief, the effect on telephone users varies. In areas in which overlays were used, this generally avoids the need for converting telephone numbers, so existing directories, business records, letterheads, business cards, advertising, and «speed-dialing» settings can retain the same phone numbers, while the overlay is used for new number allocations. The primary effect on telephone users is the necessity of remembering and dialing 10- or 11-digit numbers when only 7-digit dialing was previously permissible.

Splitting instead of overlaying generally avoids the requirement for mandatory area-code dialing within the new regions, but at the expense of having to convert a region to the new code, which necessitates updating records and directories to accommodate the new numbers. A smooth adjustment to splitting requires a period of «permissive dialing» during which the new and old codes are both allowed to work. Also, many splittings involved significant technical issues, especially when the area splittings occurred over boundaries other than phone network divisions.

As an example, in 1998, the area code 612, assigned to the Minneapolis – Saint Paul Twin Cities, was split to create a new area code 651 for St. Paul and the eastern metropolitan area. The Minnesota Public Utilities Commission mandated that the new boundary exactly follow municipal boundaries, which were distinctly different from telephone exchange boundaries, and that all subscribers keep their seven-digit numbers. These two goals were directly at odds with the reason for the split, namely to provide additional telephone numbers. More than forty exchanges had territory that straddled the new boundary. As a result, prefixes were duplicated in both area codes, which counteracted much of the benefit of the split, with only 200 of 700 prefixes in area 612 moving entirely to area 651. In less than two years, area code 612 again exhausted its supply of telephone numbers, and necessitated a three-way split in 2000, creating the new area codes 763 and 952. The split again followed political boundaries, rather than rate center boundaries, resulting in additional split prefixes; a few numbers moved from 612 to 651 to 763 in less than two years.

Decrease of growth rate[edit]

Recognizing that the proliferation of area codes was largely due to the telecom deregulation act and the assignment of numbers in blocks of ten thousand, the FCC instructed NANPA, by then administered by Neustar, to alleviate the numbering shortage. As a result, number pooling was piloted in 2001 as a system for allocating local numbers to carriers in blocks of 1,000 rather than 10,000. Because of the then design of the switched telephone network, this was a considerable technical obstacle. Number pooling was implemented with another technical obstacle, local number portability.

The program has been implemented in much of the United States by state regulators. Some cities have also implemented rate center consolidation; fewer rate centers resulted in more efficient use of telephone numbers, as carriers would reserve blocks of 1,000 or 10,000 numbers in each of multiple rate centers in the same area even if they had relatively few clients in the area.[40] (A rate center is a geographical area used by a Local Exchange Carrier (LEC) to determine the boundaries for local calling, billing and assigning phone numbers. Typically a call within a rate center is local, while a call from one rate center to another is a long-distance call.) Together with aggressive reclamation of unused number blocks from telecom providers, number pooling has reduced the need for additional area codes, so that many previously designated area splits and overlays have been postponed indefinitely.

Canada never implemented number pooling, so that even the smallest villages are rate centers and every CLEC is assigned blocks of ten thousand numbers.

New area codes outside the contiguous United States and Canada[edit]

Before 1995, all NANP countries and territories outside the contiguous United States, Alaska, Hawaii and Canada shared the area code 809. This included Puerto Rico and the U.S. Virgin Islands. Each has since been assigned one or more distinct numbering plan areas; area code 809 now exclusively serves the Dominican Republic (along with area codes 829 and 849). The United States Pacific territories of the Northern Mariana Islands and Guam joined the NANP in 1997, and American Samoa became an NANP member in October 2004. The Dutch possession of Sint Maarten was originally scheduled to join the NANP on May 31, 2010, but the changeover was postponed to September 30, 2011.[13]

Bermuda before 1995: served by area code 809 1995: assigned area code 441
Puerto Rico before 1996: served by area code 809 1996: assigned area code 787

2001: overlaid with area code 939

U.S. Virgin Islands before 1997: served by area code 809 1997: assigned area code 340
Northern Marianas before 1997: reached via IDDD using country code 670 1997: assigned area code 670
Guam before 1997: reached via IDDD using country code 671 1997: assigned area code 671
American Samoa before October 1, 2004: reached via IDDD using country code 684 2004: assigned area code 684
Sint Maarten before September 30, 2011: reached via IDDD using country code 599 2011: assigned area code 721

Telephone number size expansion[edit]

The NANP exhaust analysis estimates that the existing numbering system is sufficient beyond 2049, based on the assumptions that a maximum of 674 NPAs continue to be available, and that on average 3,990 central office codes are needed per year.[41]

In case of exhaustion, various plans are discussed for expanding the numbering plan. One option is to add the digit 1 or 0 either at the beginning or at the end of the area code, or prefixing it to the seven-digit subscriber number. This would require eleven-digit dialing even for local calls between any two NANP numbers. Another proposal introduces the digit 9 into the area code in the format x9xx, so that, for example, San Francisco’s 415 would become 4915. Other proposals include reallocating blocks of numbers assigned to smaller long-distance carriers or unused reserved services.[citation needed]

Dialing procedures[edit]

The structure of the North American Numbering Plan permits implementation of local dial plans in each plan area, depending on requirements. When multiple NPA codes serve an area in an overlay arrangement, ten-digit (10D) dialing is required. Seven-digit (7D) dialing may be permissible in areas with single area codes.[42] Depending on the requirement of toll alerting, it may be necessary to prefix a telephone number with 1. The NANPA publishes dial plan information for individual area codes.[43]

The standard dial plans in most cases are as follows:

Local within area code Local outside area code Toll within area code Toll outside area code
Single code area, with toll alerting 7D or 10D 7D or 10D 1+10D 1+10D
Single code area, without toll alerting 7D or 10D 1+10D 7D or 10D 1+10D
Overlaid area, with toll alerting 10D 10D 1+10D 1+10D
Overlaid area, without toll alerting 10D 1+10D 10D 1+10D

The number of digits dialed is unrelated to being a local call or a toll call when there is no toll alerting. Allowing 7D local dial across an area code boundary, which is uncommon today, requires central office code protection, locally if using toll alerting, across the entire area code otherwise, to avoid assignment of the same seven-digit number on both sides. Landlines occasionally require 1+10D where 10D is required, most notably in California.

Most areas permit local calls as 1+10D except for Texas, Georgia, and some jurisdictions in Canada which require that landline callers know which numbers are local and which are toll, dialing 10D for local calls and 1+10D for all toll calls.

In almost all cases, domestic operator-assisted calls are dialed 0+10D.

Special numbers and codes[edit]

Some common special numbers in the North American system:

  • 0 — operator assistance
  • 00 — long-distance operator assistance (formerly 2-1-1)
  • 011 — international access code using direct dial (for all destinations outside the NANP)
  • 01 — international access code using operator assistance (for all destinations outside the NANP)
  • 101-xxxx — used to select use of an alternative long-distance carrier
  • 211 — local community information or social services (in some cities)
  • 311 — city government or non-emergency police matters
  • 411 — local telephone directory service (Some telephone companies provide national directory assistance)
  • 511 — traffic, road, and tourist information
  • 611 — telephone line repair service (formerly 4104), wireless operator customer service (formerly 811)
  • 711 — relay service for customers with hearing or speech disabilities
  • 811 — local utility location services (United States), non-urgent telehealth/teletriage services in Canada (formerly telephone company business office)
  • 911 — emergency telephone number — fire department, medical emergency, police
  • 988 — National Suicide Prevention Lifeline (United States)[44]
  • 950-xxxx — Feature group code for access to a carrier from a non-subscriber location. The feature requires the customer dial a 950-xxxx number and enter a calling card number and destination telephone number. It was originally used for locations where 101-xxxx dialing was not possible.
  • 958-xxxx (local); 959-xxxx (long distance) — Plant test numbers, such as automatic number announcement circuits. It was once common to reserve entire unused exchange prefixes or N11 numbers (4101 was ringback number on many step-by-step switches), but these have largely moved to individual unpublished numbers within the standard 958-xxxx (local) or 959-xxxx (long-distance) plant test exchanges as numbers become scarce.
  • 1 (NPA) 555-1212 — non-local directory information (Canada and United States)

Vertical service codes are used for special calling features, such as:

  • *51 and 1151 — a history of unanswered calls on a telephone number, useful for those who are not Caller ID subscribers
  • *57 and 1157 — used to trace harassing, threatening, abusive, obscene, etc. phone calls, and keep results of trace at phone company
  • *66 and 1166 — to keep retrying a busy-line (see also Called-party camp-on)
  • *67 and 1167 — Caller ID Block
  • *69 and 1169 — Call Return (caller may press ‘1’ to return call after hearing number)
  • *70 and 1170 — cancel call waiting on a call-by-call basis
  • *71 and 1171 — three-way calling, which lets a person talk to people in two different locations at the same time
  • *74 and 1174 — speed dial, which allows someone to quickly dial any of eight frequently called numbers using a one-digit code, from any phone on their line
  • *75 — allows a total of 30 speed-call numbers with two digits
  • *77 — activates Anonymous Call Rejection Service
  • *82 and 1182 — releases Caller ID block on a call-by-call basis
  • *87 — deactivates Anonymous Call Rejection Service

The four-digit numbers are not implemented in some areas. The star codes (*) are for use on Touch-Tone telephones, whereas the four-digit numbers prefixed 11xx are used on rotary dial telephones which cannot dial the * symbol.

Not all NANP countries use the same codes. For example, the emergency telephone number is not always 911: Trinidad and Tobago and Dominica use 999, as in the United Kingdom. The country of Barbados uses 211 for police force, 311 for fire, and 511 for ambulance, while Jamaica uses 114 for directory assistance, 119 for police force, and 110 for fire and ambulance services.

Despite its early importance as a share of the worldwide telephone system, few of the NANP’s codes, such as 911, have been adopted outside the system. Determining that 911 requires unnecessary rotation time on rotary dial telephones, the European Union has adopted its own standardized number of 112, while countries in Asia and the rest of the world use a variety of other two- or three-digit emergency telephone number combinations. The 112 code is gaining prevalence because of its preprogrammed presence in mobile telephones that conform to the European GSM standard. The European Union and many other countries have chosen the International Telecommunication Union’s 00 as their international access number instead of 011. However, the toll-free prefix 800 has been widely adopted elsewhere, including as the international toll-free country code. It is often preceded by a 0 rather than a 1 in many countries where 0 is the trunk prefix.

International dialing[edit]

While international direct dialing was available in some locations in the United States by the late 1950s, a continental system was introduced as
International Direct Distance Dialing (IDDD) for the territories of the North American Numbering Plan in March 1970.[45]

While the NANP was designed as a closed numbering plan with ten digit telephone numbers, IDDD was implemented through extensive modifications in the switching systems to accommodate the international open numbering plan with seven to twelve digits in the national telephone numbers.[46] Access to the international network is facilitated by the dialing prefix 011, after which the country calling code and the national telephone number are dialed.

Number portability[edit]

The Telecommunications Act of 1996 (47 U.S.C. § 251 (b)(2)) authorizes the Federal Communications Commission (FCC) to require all local exchange carriers (LECs) to offer local number portability.[47] The FCC regulations were enacted on June 27, 1996, with changes to take effect in the one hundred largest Metropolitan Statistical Areas by October 1, 1997, and elsewhere by December 31, 1998.[48]

The FCC directed the North American Numbering Council (NANC) to select one or more private-sector candidates for the local number portability administrator (LNPA) function,[49] in a manner akin to the selection of the North American Numbering Plan Administrator (NANPA).[50]

The toll-free telephone numbers in NPA 800, 888, 877, 866, 855, 844, and 833 have been portable through the RespOrg system since 1993.[51]

Toll charges[edit]

Telephone calls between countries and territories of the NANP are not typically charged at domestic rates. For example, most long-distance plans may charge a California subscriber a higher rate for a call to British Columbia than for a call to New York, even though both destinations are within the NANP. Similarly, calls from Bermuda to U.S. destinations incur international rates. Even toll-free numbers may incur charges to callers. This is because many of the island nations implemented a plan of subsidizing the cost of local telephone services by directly charging higher pricing levies on international long-distance services.[citation needed]

Because of these higher fees, scams had taken advantage of customers’ unfamiliarity with pricing structure to call the legacy regional area code 809. Some scams lured customers from the United States and Canada into placing expensive calls to the Caribbean, by representing area code 809 as a regular domestic, low-cost, or toll-free call. The split of 809 (which formerly served all of the Caribbean NANP points) into multiple new area codes created many new, unfamiliar prefixes which could be mistaken for U.S. or Canada domestic area codes but carried high tariffs. In various island nations, premium exchanges such as +1-876-HOT-, +1-876-WET- or +1-876-SEX- (where 876 is Jamaica) became a means to circumvent consumer-protection laws governing area code 900 or similar U.S.-domestic premium numbers.

The occurrence of these scams has been on the decline, with many of the Cable and Wireless service monopolies being opened up to competition, hence lowering rates. Additionally, many Caribbean territories have implemented local government agencies to regulate telecommunications rates of providers.[52][53]

Countries and territories[edit]

Of all states or territories, the U.S. state of California has the largest number of area codes assigned, followed by Texas, Florida and New York, while most countries of the Caribbean use only one.[54] Many Caribbean codes were assigned based on alphabetic abbreviations of the territory name, as indicated in the third column of the following table (Letter code). This follows the traditional letter assignments on telephone dials. For some Pacific islands, the NANPA area code is the same as the country code that was discontinued upon membership in the NANP.

Country/Territory Area codes Letter code Regulator
 American Samoa 684* American Samoa Telecommunications Authority
 Anguilla 264 ANG Public Utilities Commission of Anguilla
 Antigua and Barbuda 268 ANT Telecommunications Division of the Government of Antigua and Barbuda
 Bahamas 242 BHA Utilities Regulation & Competition Authority
 Barbados 246 BIM Telecommunications Unit
 Bermuda 441 https://www.ra.bm/
 British Virgin Islands 284 BVI Telecommunications Regulatory Commission
Canada Canada 204, 226, … 905 Canadian Numbering Administration Consortium
 Cayman Islands 345 Information and Communications Technology Authority
 Dominica 767 ROS (Roseau) Eastern Caribbean Telecommunications Authority
 Dominican Republic 809, 829, 849 Instituto Dominicano de las Telecomunicaciones
 Grenada 473 GRE Eastern Caribbean Telecommunications Authority
 Guam 671* Guam Telephone Authority
 Jamaica 876, 658[55] Spectrum Management Authority
 Montserrat 664 Montserrat Info-Communications Authority
 Northern Mariana Islands 670*
 Puerto Rico 787, 939 PUR Junta Reglamentadora de Telecomunicaciones de Puerto Rico
 Saint Kitts and Nevis 869 National Telecommunications Regulatory Commission
 Saint Lucia 758 SLU National Telecommunications Regulatory Commission
 Saint Vincent and the Grenadines 784 SVG National Telecommunications Regulatory Commission
 Sint Maarten[13] 721 Bureau Telecommunications and Post
 Trinidad and Tobago 868 TNT Telecommunications Authority of Trinidad and Tobago
 Turks and Caicos Islands 649 Telecommunications Commission
 United States 201, 202, … 989 Federal Communications Commission
 United States Virgin Islands 340 Public Services Commission
* same as previous country code

Membership in the NANP brings significant advantages for countries in the vicinity of the United States and Canada, which usually are already the top dialing destinations. Both countries also originate most of the tourism business for the Caribbean. This is enhanced by the integration from sharing the same dialing procedures, without international access codes, and the toll-free number system of the NANP, as businesses in all member countries are eligible to participate.

Alphabetic mnemonic system[edit]

digit letters

Letters of the alphabet are mapped to the digits of the telephone dial pad.

2 ABC
3 DEF
4 GHI
5 JKL
6 MNO
7 P(Q)RS
8 TUV
9 WXY(Z)

Many telephone dials and keypads maintain a tradition of alphabetic dialing. Usually each pushbutton from digit 2 to 9 also displays three letters, which is standardized in ISO 9995-8 and, in Europe, E.161. Historically, the letters Q and Z were omitted, although some modern telephones contain them. SMS-capable devices have all 26 letters. The alphabet is apportioned to the buttons as follows:

No letters are typically mapped to keys 1 and 0, although some corporate voicemail systems use 1 for Q and Z, and some old telephones assigned the Z to the digit 0.

Originally, this scheme was used as a mnemonic device for the exchange prefixes in telephone numbers. When telephone numbers in the United States were standardized in the mid-20th century to seven digits, the first two digits of the exchange prefix were expressed as letters rather than numbers, using the telephone exchange name. Before World War II, the largest cities used three letters and four or five numerals, while in most cities phone numbers had only six digits (2L-4N). The prefix was a name and the first two or three letters, listed as capital letters in directories, were dialed. Later, the third letter, where implemented, was replaced by a digit, or an extra digit was added. This generally happened after World War II, although New York City converted in 1930. The adoption of seven-digit local numbers (2L-5N) was chosen as the requirement for direct distance dialing and progressively deployed starting in the late 1940s.

The famous Glenn Miller tune PEnnsylvania 6-5000 refers to telephone number PE6-5000, a number in service at the Hotel Pennsylvania (212 736-5000) in New York up until 2020 when the hotel closed permanently. Similarly, the classic film BUtterfield 8 is set in the East Side of Manhattan between roughly 64th and 86th Streets, where the telephone prefixes include 288.

The letter system was phased out, beginning before 1965, although it persisted ten years later in some places. It was included in Bell of Pennsylvania directories until 1983. Even today, some businesses still display a 2L-5N number in advertisements, e.g., the Belvedere Construction Company in Detroit, Michigan not only still uses the 2L-5N format for its number (TYler 8-7100), it uses the format for the toll-free number (1-800-TY8-7100).

Despite the phasing out of the letter system, alphabetic phonewords remain as a commercial mnemonic gimmick, particularly for toll-free numbers. For example, one can dial 1-800-FLOWERS to order flowers, or 1-800-DENTIST to find a local dentist.

In addition to commercial uses, alphabetic dialing has occasionally influenced the choice of area codes. For example, when area code 423 (East Tennessee) was split in 1999, the region surrounding Knoxville was assigned area code 865, chosen to represent VOL, for The Volunteer State, the nickname of Tennessee, as well as athletic teams at the University of Tennessee.[56][57] Similarly, several Caribbean area codes were chosen as an alphabetic abbreviation of the country name.

Fictional telephone numbers[edit]

American television programs and films often use the central office code 555, or KLamath 5 and KLondike 5 in older movies and shows, for fictitious telephone numbers, to prevent disturbing actual telephone subscribers if anyone is tempted to dial a telephone number seen or referred to on screen. Not all numbers beginning with 555 are fictional. For example, 555-1212 is the standard number for directory assistance. Only 555-0100 through 555-0199 are reserved for fictional use. Where used, these are often routed to information services; Canadian telephone companies briefly promoted 555-1313 as a pay-per-use «name that number» reverse lookup in the mid-1990s.[58]

Occasionally, valid telephone numbers are used as song titles. The 1962 Motown hit «Beechwood 4-5789» was written by Marvin Gaye for the Marvelettes, while Stax/Volt Records’ Wilson Pickett scored a soul hit in the 1960s with the similarly named «634-5789». A more recent example is the 1981 song «867-5309/Jenny» by Tommy Tutone, which was the cause of a large number of prank calls.[59]

Telephone number formatting[edit]

NANP telephone numbers are usually written as NPA-NXX-XXXX or (NPA) NXX-XXXX . For example, 250 555 0199, a fictional number, could be written as 250-555-0199, (250) 555-0199, 250-5550199, or 250/555-0199. The Government of Canada’s Translation Bureau recommends using hyphens between groups; e.g. 250-555-0199.[60]

Using the global formatting for telephone numbers, per recommendation E.164 by the International Telecommunication Union (ITU), a NANP number is written as +1NPANXXXXXX, without spaces or punctuation, e.g. +12505550199.

See also[edit]

  • List of area code overlays
  • List of North American Numbering Plan area codes
  • Numbering Resource Utilization/Forecast Report

References[edit]

  1. ^ «Contacts in the Countries Participating in the North American Numbering Plan» (PDF).
  2. ^ «Canadian Numbering Administrator».
  3. ^ «NANPA : Number Resources — NPA (Area) Codes». Retrieved 2015-10-23.
  4. ^ ITU; ITU-T. «The International Public Telecommunication Numbering Plan». ITU. Retrieved 2015-07-25.
  5. ^ Nunn, W. H. (1952). «Nationwide Numbering Plan». Bell System Technical Journal. 31 (5): 851–9. doi:10.1002/j.1538-7305.1952.tb01412.x.
  6. ^ «1951: First Direct-Dial Transcontinental Telephone Call». AT&T Corporation. Retrieved 2007-06-08.
  7. ^ a b c AT&T, Notes on Distance Dialing (1968).
  8. ^ AT&T, Notes on Distance Dialing (1975).
  9. ^ «NANPA: North American Numbering Plan Administration — About Us».
  10. ^ Mehta, Stephanie N. (1999-02-26). «The Kennedy Space Center Acquires A New Area Code: 3-2-1, as in Blast Off». The Wall Street Journal.
  11. ^ AT&T, Notes on the Network, Section 3, p.8 (1980)
  12. ^ Green book, Volume 2, Part 1, International Telegraph and Telephone Consultative Committee, International Telecommunication Union, 1973, page 129
  13. ^ a b c «PL-418: Introduction of NPA 721 (Sint Maarten)» (PDF). North American Numbering Plan Administration. 2011-01-05. Retrieved 2011-08-08. Updated by: «PL-423: Updated Information — Introduction of NPA 721 (Sint Maarten)» (PDF). North American Numbering Plan Administration. 2011-07-27. Retrieved 2011-08-08.
  14. ^ «About the North American Numbering Plan».
  15. ^ Bellcore Planning Letter PL-NANP-106, (1997-12-23)
  16. ^ «About NANPA». Neustar. Retrieved 2015-06-23.
  17. ^ FCC News release: FCC selects Somos as NANPA and PA under one-year bridge contract.
  18. ^ «Somos, Inc. Is Awarded the North American Numbering Plan Administration and the Pooling Administration Contracts | Somos».
  19. ^ FCC awards $75M NANPA/PA/RNDA Services contract, G2Xchange FedCiv (2020-12-01), Retrieved 2021-05-04.
  20. ^ a b c d e AT&T (1955) Notes on Nationwide Dialing
  21. ^ a b Notes on the Network, AT&T (1980)
  22. ^ W.H. Nunn, Nationwide Numbering Plan, Bell System Technical Journal 31(5), 851 (1952)
  23. ^ AT&T, Notes on the Network, Section 10, p.3 (1980).
  24. ^ John Greene (2015-01-16). «Why Did Old Phone Numbers Start With Letters?». Mental Floss. Retrieved 2019-02-01.
  25. ^ Mabbs, Ralph (Winter 1947–1948). «Nation-Wide Operator Toll Dialing—the Coming Way». Bell Telephone Magazine. 26 (4): 181. Retrieved 2022-12-26.
  26. ^ «Now You Can Call, If Your Calls Don’t Work Some Business Lines Aren’t Set Up To Call To New Area Codes» Archived 2008-03-16 at the Wayback Machine, The Virginian-Pilot, November 1, 1995. Accessed June 8, 2007. «When the first area code, 201, was introduced in New Jersey in 1951, phone-numbering experts thought there would be enough codes with a middle digit of 0 or 1 to last well into the next century.»
  27. ^ Statistical Abstract of the United States. 1960. p. 516. Retrieved 2019-02-01.
  28. ^ Bell Telephone Laboratories, A History of Engineering and Science in the Bell System — The Early Years (1875-1925), M.D. Fagan (ed.), 1975, p.126
  29. ^ a b c Blair N.D., Cosgrove M.P. (AT&T), why all numbers?, Bell Telephone Magazine, Autumn 1962, p.10
  30. ^ Alliance for Telecommunications Industry Solutions (ATIS), Numbering and Dialing Plans within the United States (ATIS-0300076), December 2008, p.7
  31. ^ AT&T, All-Number Calling Being Introduced In Bell System, Bell Laboratories Record 38(12) p.470 (December 1960)
  32. ^ Bell Telephone Laboratories, Engineering and Operations in the Bell System (1984), p.119
  33. ^ «Numbering Resources: NPA (Area) Codes». NANP. Neustar. Archived from the original on 2013-01-04. Retrieved November 13, 2021.
  34. ^ «CNA — North American Numbering Plan».
  35. ^ «NANPA : North American Numbering Plan Administration — About Us».
  36. ^ «NANP North American Numbering Plan useful facts».
  37. ^ «NANP: The North American Numbering Plan Explained». 28 December 2020.
  38. ^ North American Numbering Plan Administrator, Planning Letter PL-558, 2021-01-28.
  39. ^ See, e.g., AT&T plans, T-Mobile Magenta plans, and Verizon unlimited plans.
  40. ^ Rate Center Consolidations
  41. ^ «April 2019 North American Numbering Plan (NANP) Exhaust Analysis» (PDF). Archived from the original (PDF) on 2020-02-19.
  42. ^ «Uniform Dialing Plans».
  43. ^ «Area Codes Requiring 10 Digit Dialing».
  44. ^ «FCC Designates 988 for the National Suicide Prevention Lifeline». Federal Communications Commission. 2020-07-16. Retrieved 2021-12-06.
  45. ^ AT&T, Notes on Distance Dialing (1975)
  46. ^ AT&T, Notes on the Network, Section 10.3.02, p.3 (1980).
  47. ^ 11 FCC Rcd 8353
  48. ^ 11 FCC Rcd 8355. The regulations are located at 47 CFR 52, 47 CFR 52.20 et seq.
  49. ^ 47 CFR 1.1204
  50. ^ 11 FCC Rcd 8401
  51. ^ 10 FCC Rcd 12351
  52. ^ Administrator. «Fair Trading Commission, Barbados — Legislation».
  53. ^ «The Eastern Caribbean Telecommunications Authority (ECTEL) > Telecom regulations». Archived from the original on 2011-07-18. Retrieved 2009-03-13.
  54. ^ «United States Area Codes». www.areacodehelp.com. Retrieved 2018-09-27.
  55. ^ «Call 658 … Jamaica gets additional area code, 10-digit dialling becomes mandatory May 2018». 28 August 2017.
  56. ^ Brewer, Bill. 423 Area Code To Become VOL In 9 ET Counties. Knoxville News-Sentinel. April 17, 1999.
  57. ^ Tennessee Regulatory Authority press release, April 29, 1999
  58. ^ «Canadian telco offers users a handy reverse directory». America’s Network. 1996-05-15.
  59. ^ «867-5309/Jenny». Urban Legends Reference Pages. snopes.com. 2014-07-09. Retrieved 2017-06-28.
  60. ^ Government of Canada, Public Services and Procurement Canada (2019-12-06). «To Drop or Not to Drop Parentheses in Telephone Numbers – Favourite Articles – Writing Tools – Resources of the Language Portal of Canada – Languages – Canadian identity and society – Culture, history and sport – Canada.ca». www.noslangues-ourlanguages.gc.ca. Retrieved 2022-02-10.

External links[edit]

  • North American Numbering Plan Administrator (NANPA)
  • Canadian Numbering Administrator
  • Map of the original 86 area codes from 1947
  • North American Numbering Council Archived 2022-01-20 at the Wayback Machine
  • NANP Discussion 2003 Document — Understanding the North American Numbering Plan

Виртуальный номер США представляет собой услугу IP-телефонии, основанную на переадресации входящий вызовов. Звонки, поступающие на такой номер, направляются по заданному сценарию на другой номер стационарного или мобильного оператора, расположенного в том городе или стране, которую укажет клиент. Проще говоря, происходит небольшой обман: абонент думает, что набирает американский номер телефона, а на самом деле звонок поступает, к примеру, в Россию или Украину. При этом оплату за так называемый международный звонок берет на себя принимающая сторона, причем по тарифам, намного меньшим общепринятых.

Телефонные номера США помогают приблизиться к «американской мечте» и организовать бизнес в любом из штатов без необходимости аренды физического офиса, сохраняя при этом полную конфиденциальность переговоров. Даже если вы постоянно будете перемещаться из одной страны в другую или задумаете отправиться в кругосветное путешествие, номер менять не потребуется – он будет отлично работать везде, где есть доступ в интернет.

Как выглядит номер телефона США

Фейковые номера телефонов США внешне никак не отличаются от тех, что привыкли видеть пользователи Соединенных Штатов. Он состоит из кода страны, кода конкретного города и непосредственно номера оператора телефонной связи.

Это, например, может выглядеть так:

  • +1– международный код США;
  • (ХХХ) – код города или штата;
  • ХХХ-ХХ-ХХ – сам номер телефона.

Если собрать все воедино, получим: +1(ХХХ) ХХХ-ХХ-ХХ.

Работают телефонные номера США очень просто. Звонок поступает на сервер провайдера, предоставляющего услуги IP-телефонии, а затем отправляется абоненту в соответствии с заданными настройками. Купить номера США можно в компании Freezvon, которая имеет репутацию надежного поставщика IP-услуг.

Кто пользуется фейковыми номерами

Чаще всего пользователями такой услуги являются бизнесмены, развивающие свою деятельность на территории Америки. Фейковый номер телефона в США дает возможность:

  • наладить сотрудничество с американскими поставщиками и клиентами;
  • общаться с местными жителями по личным вопросам, не оплачивая международные звонки;
  • удешевить стоимость связи.

Также можно использовать американский номер телефона для регистрации на различных полезных ресурсах: биржах, онлайн-досках объявлений, в зарубежных интернет-магазинах. Некоторые регистрируют такой номер, чтобы попасть на удаленную работу в американскую компанию. Несмотря на то, что работать придется дистанционно, многие работодатели подсознательно отдают предпочтение «соотечественникам», с которым могут связаться по местному номеру телефона.

На самом деле, если вы регулярно общаетесь с жителями Соединенных Штатов или планируете наладить такое общение, вам просто не обойтись без «местного» виртуального номера. Чтобы убедиться в этом самостоятельно, достаточно протестировать использование такой системы связи на протяжении 1-3 месяцев – разница сразу станет очевидной.

Последнее обновление 02.12.2019, 16:53 от пользователя
Макс Вега
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Номера телефонов в Соединенных Штатах Америки имеют 10 чисел: трехзначный код штата (или мобильного оператора) и семизначный номер абонента. Если Вы звоните из другой страны, Вам потребуется также набрать код выхода, код США и номер телефона. Здесь мы расскажем, как набрать номер американского телефона из любой части мира, будь то Россия, Украина, Беларусь или иная страна.

  • Международный код США
  • Телефонные коды штатов США
  • Звонки в США
    • Звонки в США из других стран
  • Международные звонки из США

Международный код США

Международный код США: +1. Необходимо набирать этот код страны каждый раз, когда Вы звоните из-за пределов Соединенных Штатов Америки.

Телефонные коды штатов США

Код штата представляет собой трехзначный префикс. В каждом штате количество кодов штата зависит от размера и распределения его жителей. Например, штаты с более низким уровнем населения, такие как Айдахо, имеют меньше кодов областей, а более плотно населенные штаты, такие как Нью-Йорк, имеют гораздо больше кодов.

Телефонные коды штатов:

Штат Код
Алабама 205, 251, 256, 334
Аляска 907
Аризона 480, 520, 602, 623, 928
Арканзас 479, 501, 870
Калифорния 209, 213, 310, 323, 408, 415, 510, 530, 559, 562, 619, 626, 650, 661, 707, 714, 760, 805, 818, 831, 858, 909, 916, 925, 949, 951
Колорадо 303, 719, 970
Коннектикут 203, 860
Делавар 302
Флорида 239, 305, 321, 352, 386, 407, 561, 727, 772, 813, 850, 863, 904, 941, 954
Джорджия 229, 404, 478, 706, 770, 912
Гаваи 808
Айдахо 208
Иллинойз 217, 309, 312, 618, 630, 708, 773, 815, 847
Индиана 219, 260, 317, 574, 765, 812
Айова 319, 515, 563, 641, 712
Канзас 316, 620, 785, 913
Кентуки 270, 502, 606, 859
Луизиана 225, 318, 337, 504, 985
Мейн 207
Мэриленд 301, 410
Массачусетс 413, 508, 617, 781, 978
Мичиган 231, 248, 269, 313, 517, 586, 616, 734, 810, 906, 989
Миннесота 218, 320, 507, 612, 651, 763, 952
Миссиссиппи 228, 601, 662
Миссури 314, 417, 573, 636, 660, 816
Монтана 406
Небраска 308, 402
Невада 702, 775
Нью-Гемпшир 603
Нью-Джерси 201, 609, 732, 856, 908, 973
Нью-Мехико 505, 575
Нью-Йорк 212, 315, 516, 518, 585, 607, 631, 716, 718, 845, 914
Северная Каролина 252, 336, 704, 828, 910, 919
Северная Дакота 701
Огайо 216, 330, 419, 440, 513, 614, 740, 937
Оклахома 405, 580, 918
Орегон 503, 541
Пенсильвания 215, 412, 570, 610, 717, 724, 814
Род-Айленд 401
Южная Каролина 803, 843, 864
Южная Дакота 605
Теннесси 423, 615, 731, 865, 901, 931
Техас 210, 214, 254, 281, 325, 361, 409, 432, 512, 713, 806, 817, 830, 903, 915, 936, 940, 956, 972, 979
Юта 435, 801
Вермонт 802
Вирджиния 276, 434, 540, 703, 757, 804
Вашингтон 206, 253, 360, 425, 509
Washington ДС 202
Западная Вирджиния 304
Висконсин 262, 414, 608, 715, 920
Вайоминг 307

Звонки в США

Звонки в США из других стран

Если Вы звоните на номер телефона в Соединенных Штатах из других стран мира, перед кодом США и штата Вы должны набрать код выхода, действующий в Вашей стране.

Например, если Вы совершаете звонок из Российской Федерации, Вам необходимо набрать
7 1 ### ### ####.

Международные звонки из США

Если вы находитесь в Соединенных Штатах и хотите позвонить человеку, находящемуся за пределами США, наберите 011 (это международный код доступа), а затем необходимый код страны и семи- или восьмизначный номер телефона. Если номер телефона начинается с номера 0, то 0 не следует набирать.

Например, чтобы связаться с номером телефона во Франции, необходимо набрать 011 33 # ## ## ## ##.
Изображение: © James Sutton — Unsplash.com

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