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 telephone country code 1. Some North American countries, most notably Mexico, do not participate with the NANP.
A telephone numbering plan is a type of numbering scheme used in telecommunication to assign telephone numbers to subscriber telephones or other telephony endpoints. Telephone numbers are the addresses of participants in a telephone network, reachable by a system of destination code routing. Telephone numbering plans are defined in each of the administrative regions of the public switched telephone network (PSTN) and in private telephone networks.
In telecommunications, an area code overlay complex is a telephone numbering plan that assigns multiple area codes to the same geographic numbering plan area (NPA). Area code overlays are implemented in territories of the North American Numbering Plan (NANP) to mitigate exhaustion of central office codes in growth areas. The method has been in use since 1992, and has been the exclusive method of area code relief since 2007.
Ten-digit dialing is a telephone dialing procedure in the countries and territories that are members of the North American Numbering Plan (NANP). It is the practice of including the area code of a telephone number when dialing to initiate a telephone call. When necessary, the ten-digit number may be prefixed with the trunk code 1, which is referred to as 1+10-digit dialing or national format.
Area codes 706 and 762 are telephone area codes in the North American Numbering Plan (NANP) for the northern and west central parts of Georgia, but excluding metropolitan Atlanta.
Area codes 202 and 771 are telephone area codes in the North American Numbering Plan (NANP) for Washington, D.C.
Area codes 608 and 353 are telephone area codes in the North American Numbering Plan for much of southwestern Wisconsin, including the state capital city Madison. Area code 608 was assigned in 1955 to a numbering plan area created from areas with area code 414 and area code 715, and was the third area code created in Wisconsin. Rapid growth of the area, specifically in Dane County, brought the area code close to exhaustion of central office prefixes, with NANPA projections in 2022 projecting the need for relief by late 2023. In September 2022, the Wisconsin Public Service Commission and North American Numbering Plan Administrator (NANPA) announced an overlay complex for the numbering plan area with new area code 353, with an in-service date of September 15, 2023. New central office code orders were accepted starting on July 11, 2023, but activatlon is contingent on complete exhaustion of central office codes for 608.
Area codes 910 and 472 are telephone area codes in the North American Numbering Plan (NANP) for southeastern North Carolina. The area codes form an overlay for a numbering plan area (NPA) that includes the cities of Wilmington, Jacksonville, Laurinburg, Lumberton and Fayetteville. Area code 910 was established in 1993, and 472 was added to the same area in October 2022.
Area codes 704 and 980 are telephone area codes in the North American Numbering Plan (NANP) for Charlotte and all or part of 12 surrounding counties in south-central North Carolina. Other major cities in the service area are Gastonia, Kannapolis, Concord, Mooresville, Salisbury, Statesville, and Shelby. The South Carolina side of the Charlotte metropolitan area is part of area codes 803 and 839. Area code 704 is one of the original area codes assigned to numbering plan areas (NPAs) by AT&T in October 1947. Area code 980 was added in an overlay numbering plan in 2000.
Area codes 678, 470, and 943 are telephone area codes in the North American Numbering Plan (NANP) for the U.S. State of Georgia in the Atlanta metropolitan area. The area codes are assigned in an overlay plan to a combined numbering plan area (NPA) consisting of 404 and 770.
Area codes 408 and 669 are telephone area codes in the North American Numbering Plan (NANP) in the U.S. state of California. The numbering plan area comprises most of Santa Clara County and Northern Santa Cruz County, and includes Gilroy, Morgan Hill, Saratoga, Los Gatos, Monte Sereno, Milpitas, Sunnyvale, Santa Clara, Cupertino, Campbell, and San Jose.
Area codes 304 and 681 are telephone area codes in the North American Numbering Plan (NANP) for the entirety of the U.S. state of West Virginia. The numbering plan area was established in October 1947 with area code 304, as one of the eighty-six original North American area codes. Area code 681 was added to the same area in an overlay plan that took effect on March 28, 2009.
Area codes 205 and 659 are telephone area codes in the North American Numbering Plan (NANP) for the western and central parts of the U.S. State of Alabama, including the cities of Birmingham and Tuscaloosa.
Area code 912 is a telephone area code in the North American Numbering Plan (NANP) for the southeastern part of the U.S. state of Georgia. The numbering plan area contains Savannah, Richmond Hill, Hinesville, Vidalia, Metter, Reidsville, Homerville, Waycross, Brunswick, Folkston, Douglas, Statesboro, Ludowici, Jesup and Kingsland. The area code was created in 1954 in an area code split from area code 404, which had been assigned to the entire state in 1947.
Area codes 440 and 436 are telephone area codes in the North American Numbering Plan (NANP) for the U.S. state of Ohio, serving the parts of the Greater Cleveland area, surrounding the city of Cleveland, but not the city and most of its inner suburbs.
Area codes 843 and 854 are telephone area codes in the North American Numbering Plan (NANP) for a portion of the U.S. state of South Carolina that comprises roughly the eastern third and the southern tip. The numbering plan area (NPA) includes the Grand Strand, the Lowcountry, the Pee Dee, and the Sandhills. Major cities in the region are Myrtle Beach, Charleston, Beaufort, Hilton Head Island and Florence. Area code 843 was created in 1998 when area code 803 was split, while 854 was added in 2015 to form an all-services overlay.
Area codes 864 and 821 are telephone area codes in the North American Numbering Plan (NANP) for the western third of the U.S. state of South Carolina. The numbering plan area (NPA) comprises the areas of Greenville, Spartanburg, Anderson, and twelve surrounding counties. Other cities in the 864/821 territory include Clemson, Gaffney, Greer, and Mauldin. It is largely coextensive with the Upstate region.
Area codes 503 and 971 are telephone area codes in the North American Numbering Plan (NANP) for the northwestern region of the U.S. state of Oregon. The numbering plan area (NPA) comprises the cities of Portland, Salem, and Astoria. Area code 503 was one of the original North American area codes of 1947, assigned to the entire state until 1995, when its extent was reduced to the northwestern corner. Area code 971 was assigned to the service area in stages, completed in 2008, to form an overlay in the area with ten-digit dialing.
Area codes 919 and 984 are telephone area codes in the North American Numbering Plan (NANP) for all or parts of eleven counties in the east-central area of the U.S. state of North Carolina. They service the cities of Raleigh, Durham, Cary, and Chapel Hill/Carrboro, and the surrounding suburban areas of the Research Triangle metropolitan area, as well as the outlying towns and nearby rural areas of Oxford to the north, Sanford to the south, Goldsboro to the southeast, and Mebane to the west.
