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Area Codes In The United States
The North American Numbering Plan (NANP) divides the territories of its members into geographic numbering plan areas (NPAs). Each NPA is identified by one or more numbering plan area codes (''NPA codes'', or '' area codes''), consisting of three digits that are prefixed to each local telephone number having seven digits. Numbering plan areas may be assigned multiple area codes to provide adequate numbering resources, in which case the local numbering plan is called an overlay. Area codes are also assigned for non-geographic purposes. The rules for numbering NPAs do not permit the digits ''0'' and ''1'' as the leading digit, which also applies for central office codes.AT&T (1955) ''Notes on Distance Dialing'' NPAs with ''9'' as the second digit are reserved for future format expansion. Area codes with two identical trailing digits are considered easily recognizable codes (ERC), which are reserved, or used for systemwide services. Area codes in numerical order 200–299 300–399 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NANP Countries
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 NANP was 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 and prepare the continent for direct-dialing of calls by customers without the involvement of telephone operators. AT&T continued to administer the numbering plan 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
