Area code 412 is a telephone

area code 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, rea ...

in the

North American Numbering Plan 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 international callin ...

(NANP) for the

Commonwealth A commonwealth is a traditional English term for a political community founded for the common good. Historically, it has been synonymous with "republic". The noun "commonwealth", meaning "public welfare, general good or advantage", dates from the ...

Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

. The numbering plan area (NPA) comprises the city of

Pittsburgh Pittsburgh ( ) is a city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, United States, and the county seat of Allegheny County, Pennsylvania, Allegheny County. It is the most populous city in both Allegheny County and Wester ...

, most of surrounding Allegheny County, and small portions of

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

and Westmoreland counties. The area code was one of the

original North American area codes The original North American area codes were established by the American Telephone & Telegraph Company (AT&T) in 1947, following the demonstration of regional Operator Toll Dialing during the World War II period. The program had the goal of speedin ...

created in 1947, when it was assigned to the entire southwestern corner of the state.

History

When the

American Telephone and Telegraph Company AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the world's largest telecommunications company by revenue and the third largest provider of mobile tel ...

(AT&T) created the first nationwide

telephone numbering plan A telephone numbering plan is a type of numbering scheme used in telecommunication to assign telephone number A telephone number is a sequence of digits assigned to a landline telephone subscriber station connected to a telephone line or ...

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 old 412 territory outside of Allegheny County was split off and received

area code 724 Area code 724 is a Commonwealth of Pennsylvania telephone area code in western and southwestern Pennsylvania, including most of the suburbs of Pittsburgh. It was split from area code 412 on February 1, 1998. Originally, Bell Atlantic wanted to i ...

, surrounding 412.

Bell Atlantic Verizon Communications Inc., commonly known as Verizon, is an American multinational telecommunications conglomerate and a corporate component of the Dow Jones Industrial Average. The company is headquartered at 1095 Avenue of the Americas in ...

, the main telephone provider at the time in Pennsylvania, preferred to implement it as an

overlay Overlay may refer to: Computers *Overlay network, a computer network which is built on top of another network *Hardware overlay, one type of video overlay that uses memory dedicated to the application *Another term for exec, replacing one process ...

to spare residents and businesses the burden of changing telephone numbers. However, overlays were still a new concept at the time, and met with some resistance because of the need for

ten-digit dialing 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 telep ...

. As a result, 724 was implemented as an

area code split In telecommunications, an area code split is the practice of introducing a new telephone area code by geographically dividing an existing numbering plan area (NPA), and assigning area codes to the resulting divisions, but retaining the existing ar ...

, 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 Area code 878 is an overlay area code in Southwestern Pennsylvania, centered in Pittsburgh. It simultaneously overlays the region's two existing area codes, 412 and 724, making ten-digit dialing mandatory in the Pittsburgh area. 412 had served ...

was overlaid onto both 412 and 724 on August 17, 2001. 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

Consolidated Communications Consolidated Communications Holdings, Inc., doing business as Consolidated Communications, is an American broadband and business communications provider headquartered in Mattoon, Illinois. The company provides data, internet, voice, managed an ...

, formerly North Pittsburgh Telephone Company, and parts of Washington and Westmoreland counties. Specifically, it comprises the following municipalities:

Bethel Park Bethel Park, officially the Municipality of Bethel Park, is a borough with home rule status in Allegheny County, Pennsylvania, United States. It is part of the Pittsburgh metropolitan area, located approximately southwest of Pittsburgh. The po ...

Penn Hills Penn Hills is a township with home rule status in Allegheny County, Pennsylvania, United States. The population was 41,059 as of the 2020 census. Penn Hills is the second-largest municipality in Allegheny County, after Pittsburgh. History In 178 ...

Plum A plum is a fruit of some species in ''Prunus'' subg. ''Prunus'.'' Dried plums are called prunes. History Plums may have been one of the first fruits domesticated by humans. Three of the most abundantly cultivated species are not found i ...

, Carnegie,

West Mifflin West Mifflin is a borough in Allegheny County, Pennsylvania, United States, located southeast of downtown Pittsburgh. The population was 20,313 at the 2010 census. It is named after Thomas Mifflin, 1st Governor of Pennsylvania, signer of the Un ...

Fox Chapel Fox Chapel is a borough in Allegheny County, Pennsylvania, USA, and is an affluent suburb of Pittsburgh located northeast of downtown. The borough continually garners national prominence and is home to many of the wealthiest and most powerful p ...

, Franklin Park, McCandless,

McKeesport McKeesport is a city in Allegheny County, Pennsylvania, United States. It is situated at the confluence of the Monongahela River, Monongahela and Youghiogheny River, Youghiogheny rivers and within the Pittsburgh metropolitan area. The population ...

, Millvale, Monroeville,

Mount Lebanon Mount Lebanon ( ar, جَبَل لُبْنَان, ''jabal lubnān'', ; syr, ܛܘܪ ܠܒ݂ܢܢ, ', , ''ṭūr lewnōn'' french: Mont Liban) is a mountain range in Lebanon. It averages above in elevation, with its peak at . Geography The Mount Le ...

, Mount Oliver, Oakmont, Robinson Township, Ross Township, Sewickley, Shaler Township,

South Fayette South Fayette Township is a township in Allegheny County, Pennsylvania, United States. The population was 14,416 at the 2010 census. History Throughout its early history, South Fayette Township was the site of numerous conflicts between the ea ...

, Upper Saint Clair, The Borough West View

External links

{{coord, 40.488, -79.892, type:adm2nd_globe:earth_region:US-PA, display=title Telecommunications-related introductions in 1947 412 412

History

Service area

See also

External links