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 during the early 1950s, AT&T and the Bell System developed the North American Numbering Plan (NANP) during the 1940s. The plan divided the United States and Canada into numbering plan areas (NPAs) and assigned a three-digit dialing prefix to each. During the decade following introduction of these routing codes, local subscriber numbers were standardized to seven digits. This included a three-digit regional office prefix (the exchange number), dialed as the first two letters of the local exchange name followed by one digit, and the four-digit subscriber station number (the identifier for an individual telephone).[1]
The first digit of an 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 long-distance desk.[1] The original numbering plan defined the second digit of all area codes as either 0 or 1, to distinguish them from the exchange 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.[2]
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.[3] 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.[4]
Initially, the numbering plan area codes were used for Nationwide Operator Toll Dialing by long-distance operators for routing trunk calls.[5] Preparations proceeded for end-customer direct distance dialing (DDD) and while the first customer-dialed call using an area code was made on November 10, 1951, from Englewood, New Jersey, to Alameda, California,[6] it was not until the 1960s that direct distance dialing was common in most cities.
Area code | Assigned state, province, or region |
---|---|
201 | New Jersey |
202 | District of Columbia |
203 | Connecticut |
204 | Manitoba |
205 | Alabama |
206 | Washington |
207 | Maine |
208 | Idaho |
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) |
217 | Illinois (central) |
218 | Minnesota (except southeastern part of state) |
301 | Maryland |
302 | Delaware |
303 | Colorado |
304 | West Virginia |
305 | Florida |
306 | Saskatchewan |
307 | Wyoming |
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) |
401 | Rhode Island |
402 | Nebraska |
403 | Alberta |
404 | Georgia |
405 | Oklahoma |
406 | Montana |
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) |
501 | Arkansas |
502 | Kentucky |
503 | Oregon |
504 | Louisiana |
505 | New Mexico |
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) |
601 | Mississippi |
602 | Arizona |
603 | New Hampshire |
604 | British Columbia |
605 | South Dakota |
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) |
701 | North Dakota |
702 | Nevada |
703 | Virginia |
704 | North Carolina |
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) |
801 | Utah |
802 | Vermont |
803 | South Carolina |
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) |
901 | Tennessee |
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) |
References
- AT&T (1955), Notes on Nationwide Dialing, pp.3
- "Our Numbered Days: The Evolution of the Area Code". The Atlantic. 2014-02-13. Retrieved 2014-08-28.
- "Atlanta Telephone History". Atlantatelephonehistory.info. 1968-06-29. Retrieved 2014-08-28.
- "LincMad's 1947 Area Code Map". Lincmad.com. Retrieved 2014-08-28.
- 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 2014-08-28.