Seven-digit dialing

Seven-digit dialing

7-digit dialing is a popular term referring to the traditional convention in the United States and Canada for dialing local phone calls. It is also sometimes known as "local format" or "network format".

Within the multi-national calling area administered by NANPA, telephone numbers are segmented into fixed-length fields:
* a 3-digit area code, indicating a large geographical (or heavily populated) area, such as a metropolitan area or a whole state (or special service, such as toll free numbers)
* a 3-digit exchange, indicating (amongst others) a city or other municipal area
* a 4-digit station number

Traditionally, calling from one area code to another, specifically for long distance calls, requires the caller to dial the trunk digit "1" before the code and number. More recently, with the increasing number and decreasing geographic size of area codes, it is possible to call a number in another area code that is not long distance, and such a call does require the area code, but not the trunk digit (initial "1").

Before the advent of overlay plans, it was universally accepted (and in some cases, required) that a call to a number in the same area code as the calling station be dialed without including the area code. As a result, the caller only has to dial the 7 digits of the exchange plus station number.

It was and is also possible to make a long distance call within the same area code; in this case the caller has to dial a "1" before the local "7-digit" number. Until recently, in some cases, including the area code when dialing such a number would confuse the telephone system, and prevent the call from being connected.

This convention did not have a name until overlay plans introduced a requirement in some areas that all calls, even local, must be dialed by including the area code, i.e. 10-digit dialing.

Many modern cellular phones will automatically include the area code of the phone in the dialed number if the user only enters 7 digits. Although the caller only dials 7 digits, in this case the number dialed out to the phone network is actually 10 digits.

ee also

*10-digit dialing
*NANPA
*overlay plan
*list of country calling codes
*E.164


Wikimedia Foundation. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • Direct distance dialing — (DDD) or direct dial is a telecommunications term for a network provided service feature in which a call originator may, without operator assistance, call any other user outside the local calling area. DDD requires more digits in the number… …   Wikipedia

  • Direct Inward Dialing — (DID), also called Direct Dial In (DDI) in Europe, is a feature offered by telephone companies for use with their customers PBX systems, whereby the telephone company (telco) allocates a range of numbers all connected to their customer s PBX. As… …   Wikipedia

  • Area codes 519 and 226 — 519 (number) redirects here. For the number, see 500 (number). 519 is the telephone area code which covers most of southwestern Ontario and was introduced in 1953 from portions of area codes 416 and 613. In 1957, parts of 519 and 613 formed 705.… …   Wikipedia

  • Area code 404 — covers Atlanta and its immediate neighbors, roughly within Interstate 285.Originally, it covered all of Georgia when the area code system was first created in the 1940s and implemented in 1951. On July 1, 1954, area code 912 was assigned to… …   Wikipedia

  • Telephone numbering plan — Area Code redirects here. For the song by Ludacris, see Area Codes (song). A telephone numbering plan is a type of numbering scheme used in telecommunications to allocate telephone numbers to subscribers and to route telephone calls in a… …   Wikipedia

  • North American Numbering Plan — NANPA redirects here. For other uses, see Nanpa (disambiguation). This article is about the numbering plan. For a list of area codes under the plan, see List of North American Numbering Plan area codes. The North American Numbering Plan (NANP) is …   Wikipedia

  • North American numbering plan expansion — The North American numbering plan expansion is a proposed expansion of the North American Numbering Plan to accommodate future needs beyond the current 10 digit limitations used in telephone numbers.HistoryThe North American Numbering Plan has… …   Wikipedia

  • North American Numbering Plan expansion — The North American numbering plan expansion is a proposed expansion of the North American Numbering Plan to accommodate future needs beyond the current 10 digit limitations used in telephone numbers. Contents 1 History 2 Current industry… …   Wikipedia

  • Toll-free telephone number — A toll free, Freecall, Freephone, or 800 number is a special telephone number, in that the called party is charged the cost of the calls by the telephone carrier, instead of the calling party. The cost of the call to the called party is usually… …   Wikipedia

  • Telephone numbers in Turkey — Turkey went from six (2+4) to seven digits (3+4) local phone numbers c.1988, at which time Ankara went from 41 to 4.There used to be more than 5000 local area codes of varying lengths (one to five digits) with correspondingly varying local number …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”