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 during the 1940s. The plan divided the United States and Canada into numbering plan areas 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, dialed as the first two letters of the local exchange name followed by one digit, and the four-digit subscriber station number.
The first digit of an area code was never 0 or 1, as a single leading pulse was ignored by most switching equipment, and 0 could be confused with requests for an operator or 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 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.
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 for Nationwide Operator Toll Dialing by long-distance operators for routing trunk calls. Preparations proceeded for end-customer direct distance dialing and while the first customer-dialed call using an area code was made on November 10, 1951, from Englewood, New Jersey, to Alameda, California, it was not until the 1960s that direct distance dialing was common in most cities.
Area codeAssigned state, province, or region
201New Jersey
202District of Columbia
203Connecticut
204Manitoba
205Alabama
206Washington
207Maine
208Idaho
212New York
213California
214Texas
215Pennsylvania
216Ohio
217Illinois
218Minnesota
301Maryland
302Delaware
303Colorado
304West Virginia
305Florida
306Saskatchewan
307Wyoming
312Illinois
313Michigan
314Missouri
315New York
316Kansas
317Indiana
319Iowa
401Rhode Island
402Nebraska
403Alberta
404Georgia
405Oklahoma
406Montana
412Pennsylvania
413Massachusetts
414Wisconsin
415California
416Ontario
418Quebec
419Ohio
501Arkansas
502Kentucky
503Oregon
504Louisiana
505New Mexico
512Texas
513Ohio
514Quebec
515Iowa
517Michigan
518New York
601Mississippi
602Arizona
603New Hampshire
604British Columbia
605South Dakota
612Minnesota
613Ontario
614Ohio
616Michigan
617Massachusetts
618Illinois
701North Dakota
702Nevada
703Virginia
704North Carolina
712Iowa
713Texas
715Wisconsin
716New York
717Pennsylvania
801Utah
802Vermont
803South Carolina
812Indiana
814Pennsylvania
815Illinois
816Missouri
901Tennessee
902Nova Scotia, Prince Edward Island, New Brunswick
913Kansas
914New York
915Texas
916California