List of original NANP area codes
This is the list of original North American Numbering Plan area codes of 86 plan areas as defined by AT&T in 1947.
In preparation for direct distance dialing, AT&T and the Bell System developed the North American Numbering Plan in the 1940s. The plan divided the United States and Canada into numbering plan areas (NPAs) and assigned a three-digit dialing prefix to each. Over the course of the decade following introduction of these routing codes, local subscriber numbers were standardized to seven digits. This included a three-digit central office prefix, dialed as the first two letters of the local central office name and one digit, and the four-digit subscriber station number.
The first digit of the area code was never 0 or 1, as a single leading pulse (1) was ignored by most switching equipment, and 0 could be confused with requests for an operator or the long-distance desk. The original numbering plan defined the second digit of all area codes as either 0 or 1, to distinguish them from the central office codes, which always used a letter in the middle position, as letters were mapped on the dial only to digits 2 through 9. Area codes with the middle digit 0 were assigned to numbering plan areas that covered an entire state or province, while jurisdictions with multiple plan areas received area codes having 1 as the second digit.
No codes of the form N00, N10 or N11 occurred in the original area code allocation, where N is 2 through 9, creating a total of 136 possible combinations. The series N00 was used for non-geographic numbers, starting with intrastate toll-free 800-numbers in 1966. N10 numbers were originally teletypewriter exchanges and N11 remains reserved for information and emergency numbers. No codes were originally assigned to territories of the United States, including Alaska and Hawaii.
Initially, the numbering plan area codes were used in Nationwide Operator Toll Dialing by long-distance operators for placing trunk calls. Preparations proceeded for end-customer direct distance dialing (DDD) and while the first customer-dialed call using an area code was placed on November 10, 1951, from Englewood, New Jersey, to Alameda, California, it took until the 1960s until direct distance dialing was commonplace in most cities.
|Area code||Assigned state, province, or region|
|202||District of Columbia|
|212||New York (New York City)|
|213||California (Southern California, including Los Angeles)|
|214||Texas (northeastern Texas, including Dallas/Fort Worth)|
|215||Pennsylvania (southeastern Pennsylvania, including Philadelphia)|
|216||Ohio (northeastern Ohio, including Cleveland)|
|218||Minnesota (except southeastern part of state)|
|312||Illinois (Chicago metropolitan area)|
|313||Michigan (southeast Michigan, including Detroit)|
|314||Missouri (eastern Missouri, including St. Louis)|
|315||New York (central upstate New York, including Syracuse)|
|316||Kansas (southern half of Kansas)|
|317||Indiana (northern two-thirds of Indiana, including Indianapolis)|
|319||Iowa (eastern third of Iowa)|
|412||Pennsylvania (western Pennsylvania, including Pittsburgh)|
|413||Massachusetts (western Massachusetts, including Springfield)|
|414||Wisconsin (southern and northeastern Wisconsin, including Milwaukee)|
|415||California (northern/central California, including San Francisco and Sacramento)|
|416||Ontario (southern portion from Cobourg to Kitchener, including Toronto)|
|418||Quebec (eastern half of Quebec, including Québec City)|
|419||Ohio (northwest Ohio, including Toledo)|
|512||Texas (central and southern Texas, including Austin and San Antonio)|
|513||Ohio (southwest Ohio, including Cincinnati)|
|514||Quebec (western half of Quebec, including Montreal)|
|515||Iowa (central Iowa, including Des Moines)|
|517||Michigan (south-central portion of Lower Peninsula, including Lansing)|
|518||New York (northeastern New York, including Albany)|
|612||Minnesota (southeastern portion, including Minneapolis)|
|613||Ontario (all except a southern portion covering Oshawa-Toronto-Kitchener)|
|614||Ohio (southeast, including Columbus)|
|616||Michigan (Grand Rapids, Upper Peninsula, western portion of Lower Peninsula)|
|617||Massachusetts (eastern Massachusetts, including Boston)|
|618||Illinois (southern Illinois, including East St. Louis and Carbondale)|
|712||Iowa (western third, including Sioux City)|
|713||Texas (southeastern Texas, including Houston)|
|715||Wisconsin (northern Wisconsin)|
|716||New York (western New York, including Buffalo and Rochester)|
|717||Pennsylvania (eastern half, except for the Delaware and Lehigh Valleys)|
|812||Indiana (southern Indiana)|
|814||Pennsylvania (northwestern and central Pennsylvania)|
|815||Illinois (northern Illinois, except Chicago and Quad Cities)|
|816||Missouri (northwestern Missouri, including Kansas City)|
|902||Nova Scotia, Prince Edward Island, New Brunswick|
|913||Kansas (northern half of Kansas)|
|914||New York (southern New York, including Long Island, but excluding New York City)|
|915||Texas (western Texas, including El Paso)|
|916||California (northern California, but not including Sacramento)|
- AT&T (1955), Notes on Nationwide Dialing, pp.3
- "Our Numbered Days: The Evolution of the Area Code". The Atlantic. 2014-02-13. Retrieved 2016-08-28.
- "Atlanta Telephone History". Atlantatelephonehistory.info. 1968-06-29. Retrieved 2016-08-28.
- "LincMad's 1947 Area Code Map". Lincmad.com. Retrieved 2016-08-28.
- Ralph Mabbs, Nation-Wide Operator Toll Dialing—the Coming Way, Bell Telephone Magazine 1947 p.180
- "AT&T Labs Fosters Innovative Technology | AT&T Labs". Corp.att.com. Retrieved 2016-08-28.