Area code 412
Area code 412 is a Commonwealth of Pennsylvania telephone area code which serves Pittsburgh, most of surrounding Allegheny County (except the northern edge of Allegheny County served by Consolidated Communications, formerly the North Pittsburgh Telephone Company) and small portions of Washington and Westmoreland counties.
Area code 412 was one of the original area codes established in 1947. It originally covered the entire southwestern corner of the state, from Butler County to the West Virginia border. Given the rotary dialing technology in use at the time, the North American Numbering Plan Administrator wanted to keep the number of "clicks" to a minimum for large cities. For this reason, Pittsburgh was given an area code with seven clicks.
On February 1, 1998, nearly all of the old 412 territory outside of Allegheny County was split off into area code 724, which surrounds 412. Bell Atlantic, the main telephone provider in Pennsylvania, preferred to implement it as an overlay in order to spare residents the burden of changing their numbers. However, overlays were still a new concept at the time, and met with some resistance due to the need for ten-digit dialing. For this reason, 724 was implemented as a split.
This was intended as a long-term solution, but within two years both 412 and 724 were close to exhaustion once again due to the proliferation of cell phones and pagers. By this time, overlays had gained more acceptance, and for this reason area code 878 was overlaid onto both 412 and 724 on August 17, 2001. Although numbers were not assigned in 878 until 2013, ten-digit dialing has been mandatory across southwestern Pennsylvania since 2001.
Major locations in Pennsylvania using this area code
Pittsburgh, Bethel Park, Penn Hills, Plum, Carnegie, West Mifflin, Fox Chapel, Franklin Park, McCandless, McKeesport, Monroeville, Mount Lebanon, Mount Oliver, Oakmont, Robinson Township, Ross Township, Sewickley, Shaler Township, South Fayette, Upper Saint Clair, The Borough West View
The master list for Pennsylvania may be found at List of Pennsylvania area codes.
|Pennsylvania area codes: 215, 267, 412, 484, 570, 610, 717, 724, 814, 878|
|West: 724/878||Area code 412, overlaid and surrounded by 878||East: 724/878|