Area code 412

Coordinates: 40°29′17″N 79°53′31″W / 40.488°N 79.892°W / 40.488; -79.892
Source: Wikipedia, the free encyclopedia.
Area code 412Area code 716Area code 585Area code 607Area code 845Area codes 973 and 862Area code 908Area codes 410 and 443Area code 302Area codes 240 and 301Area codes 304 and 681Area codes 330 and 234Area code 440Area code 724Area code 878Area code 724Area code 814Area codes 272 and 570Area codes 610, 484, and 835Area code 856Area codes 215, 267, and 445Area codes 609 and 640Area codes 223 and 717Area code 412
Pennsylvania (blue) with numbering plan area 412 shown in red.

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.[1]
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.

History

When the

American Telephone and Telegraph Company (AT&T) created the first nationwide telephone numbering plan
for the continental United States and Canada in 1947, Pennsylvania was divided into four numbering plan areas. Area code 412 was assigned to the southwestern part of the state, from Butler County to the West Virginia border.

On February 1, 1998, nearly all of the territory outside of Allegheny County was separated as a new numbering plan area, receiveing

overlay to spare residents and businesses the burden of changing telephone numbers, but overlays were still a new concept, and were met with resistance because of the need for ten-digit dialing. As a result, 724 was implemented as an area code split
, making it one of the six pairs of doughnut area codes in North America.

This configuration was intended as a long-term solution, but within two years both 412 and 724 still experienced high demand for telephone services from the proliferation of cell phones and pagers, so that further relief became necessary. By this time, overlays had gained more acceptance, so that area code 878 was overlaid onto both 412 and 724 on August 17, 2001.[2] Although telephone numbers were not assigned for 878 until 2013 (and were only assigned in the 724 area until 2015), ten-digit dialing has been mandatory across southwestern Pennsylvania since 2001.

Service area

The numbering plan area includes Allegheny county with the exception of its northern edge served by

Shaler Township, South Fayette, Upper Saint Clair, The Borough West View

See also

References

  1. ^ Mabbs, Ralph (Winter 1947–1948). "Nation-Wide Operator Toll Dialing—the Coming Way". Bell Telephone Magazine. 26 (4): 181. Retrieved 2022-04-23.
  2. ^ "Planning Letter PL-281: Rationing in NPAs 412, 724, and 878 (Pennsylvania)" (PDF). NANPA. 2001-05-14. Retrieved 2023-06-23.

External links

484/610, 724, 814/582, 878
North: 724/878
West: 724/878 412/878 East: 724/878
South: 724/878

40°29′17″N 79°53′31″W / 40.488°N 79.892°W / 40.488; -79.892

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