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 in 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 a 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 212, 646, and 332 are area codes in the North American Numbering Plan (NANP) for most of the borough of Manhattan in New York City. By area, it is one of the smallest numbering plan areas (NPAs). The three area codes form an overlay numbering plan, and are also overlaid by area code 917 of a numbering plan area that comprises the entirety of New York City. Area code 212 is the original code assigned for all of the city in 1947. After a restriction of 212 to just Manhattan in 1985, area code 646 was assigned to Manhattan in 1999. In 2015, area code 332 was also added to the Manhattan overlay.
Area code 917 is a telephone area code in the North American Numbering Plan for the five boroughs of New York City: The Bronx, Brooklyn, Manhattan, Queens, and Staten Island. It is an overlay code to all numbering plan areas (NPAs) in the city, and was intended to serve cellular, pager, and voicemail applications in the city, a restriction that was subsequently ruled impermissible by the Federal Communications Commission (FCC) while grandfathering that use in New York City. Area code 917 is also assigned to landlines predominantly in Manhattan, to relieve the shortage of numbers there.
Area codes 516 and 363 are telephone overlay area codes in the North American Numbering Plan (NANP) for the U.S. state of New York. The numbering plan area (NPA) comprises Nassau County on Long Island. Area code 516 was created in 1951 and 363 was added to the numbering plan area in 2023.
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 610, 484, and 835 are telephone area codes in the North American Numbering Plan (NANP) for the eastern and southeastern regions of Pennsylvania. The numbering plan area (NPA) includes regions to the west of Philadelphia and the cities Allentown, Bethlehem, and Reading. It includes much of the Delaware Valley, including almost all of Delaware County, most of the Philadelphia Main Line, and all of the Lehigh Valley.
Area codes 570 and 272 are telephone area codes in the North American Numbering Plan (NANP) for the northeast quadrant of the U.S. state of Pennsylvania. The numbering plan area (NPA) includes the cities or towns of Scranton, Wilkes-Barre, Williamsport, Stroudsburg, East Stroudsburg, Pittston, Carbondale, Hazleton, Clarks Summit, Towanda, Bloomsburg, Sayre, Tunkhannock, Berwick, Milford, Montrose, Honesdale, Pocono Pines, Nanticoke, Tamaqua, Shavertown, Dallas, Mahanoy City, Sunbury, Jim Thorpe, and as far south as Pottsville and as far west as Lock Haven.
Area codes 215, 267, and 445 are telephone area codes in the North American Numbering Plan (NANP) for Philadelphia and adjacent portions of Bucks and Montgomery counties in the U.S. state of Pennsylvania. Area code 215 was one of the original North American area codes established in 1947, while 267 and 445 are overlay codes for the same numbering plan area (NPA).
Area codes 301, 240, and 227 are telephone area codes in the North American Numbering Plan (NANP) for the western part of the U.S. state of Maryland. The numbering plan area (NPA) comprises Maryland's portion of the Greater Washington, D.C. metro area, portions of southern Maryland, along with rural western Maryland. This includes the communities of Cumberland, Frederick, Hagerstown, Gaithersburg, Potomac, Germantown, Bethesda, Rockville, Landover, Silver Spring, and Waldorf.
Area codes 814 and 582 are telephone area codes in the North American Numbering Plan (NANP) for the northwestern and central portions of the Commonwealth of Pennsylvania. Cities served by the area code include Altoona, Bradford, DuBois, Erie, Meadville, Oil City, Titusville, Johnstown, St. Marys, and Warren as well as the boroughs of State College, Brockway, Clearfield, Huntingdon, Mount Union, Bedford, Clarion, Punxsutawney, Tyrone, Ebensburg, Coudersport, Ridgway and Brookville. Area code 814 is the original area code assigned to the numbering plan area in 1947. Area code 582 was activated in the service area as an additional code to form an overlay numbering plan with a starting date of October 3, 2020.
Area codes 217 and 447 are telephone area codes in the North American Numbering Plan (NANP) for much of the central part of the U.S. state of Illinois. The numbering plan area (NPA) includes the state capital, Springfield, and Champaign, Urbana, Decatur, Taylorville, Lincoln, Danville, Effingham, Quincy, Rantoul, and Jacksonville. 217 was one of the original North American area codes created in 1947 and 447 was added to the same area in 2021 to form an all-services overlay.
Area code 412 is a telephone area code in the North American Numbering Plan (NANP) for the Commonwealth of Pennsylvania. The numbering plan area (NPA) comprises the city of Pittsburgh, most of surrounding Allegheny County, and small portions of Washington and Westmoreland counties. The area code was one of the original North American area codes created in 1947, when it was assigned to the entire southwestern corner of the state. On August 17, 2001, the numbering plan area was converted to an overlay complex with area code 878, which also forms an overlay with area code 724, in the surroundings of the 412 service area.
Area codes 973 and 862 are telephone area codes in the North American Numbering Plan (NANP) in the northernmost part of the U.S. state of New Jersey. The numbering plan area (NPA) comprises the counties, or parts, of Bergen, Essex, Hudson, Morris, Passaic, Sussex and Union Counties. Cities in this service area include Newark, Paterson, Clifton, Passaic, Montclair, Morristown, Parsippany, Dover, Maplewood, and The Oranges.
Area code 878 is an area code in the North American Numbering Plan for Southwestern Pennsylvania, centered in Pittsburgh. It forms an overlay complex with two distinct numbering plan areas, 412 in Pittsburgh and some suburban areas and 724 in surrounding 412 in the southwestern corner of the state. Area code 878 was activated on August 17, 2001.
Area codes 618 and 730 are telephone area codes in the North American Numbering Plan (NANP) for southern Illinois. The numbering plan area (NPA) comprises one hundred and twenty-six municipalities, such as Carbondale, Cairo, Belleville, East St. Louis, Edwardsville, Marion, O'Fallon, Alton, Mt. Vernon, Centralia, Herrin, Salem, Metropolis, Fairview Heights, Collinsville, and Granite City. Area code 618 was one of the original North American area codes created in 1947, and 730 was added to the plan area to form an overlay complex to satisfy the need for more telephone numbers in the region.
