WHAT YOU NEED TO KNOW
Area code 878 serves the Pittsburgh metro area in western Pennsylvania, including Pittsburgh, McKeesport, Bethel Park, and Monroeville. Established in August 2001 as an overlay of area code 412, it covers approximately 2.4 million residents across multiple counties and is used alongside 412 for local phone number assignments throughout the region.
- Population: ~2.4 million residents in the metro
- Overlay: Overlay: 412
- Dialing: 10-digit dialing required
- Source Type: Local geographic code
Geographic Coverage
Area code 878 covers a broad swath of western Pennsylvania centered on Allegheny County, which contains Pittsburgh and its inner suburbs such as Bethel Park, Monroeville, and McKeesport. The code also extends into surrounding counties including Westmoreland, Butler, Beaver, Washington, Greene, Fayette, Armstrong, Lawrence, and Indiana counties. Cities like Greensburg, Butler, Canonsburg, Washington, New Castle, Beaver Falls, Uniontown, Connellsville, Kittanning, Indiana, and Waynesburg all fall within the overlay zone.
Population and Business Context
The Pittsburgh metro served by area code 878 is a significant regional market with a population of roughly 2.4 million. The area has historically been tied to steel and manufacturing, but the economy has diversified substantially into healthcare, education, technology, and financial services. Major employers include UPMC, Carnegie Mellon University, the University of Pittsburgh, and a growing cluster of robotics and artificial intelligence companies. Small and mid-size businesses make up the bulk of the local commercial landscape.
Area Code History
Area code 412 was one of the original North American Numbering Plan codes assigned in 1947, covering most of western Pennsylvania for decades. By the late 1990s, increased demand for phone numbers driven by fax machines, pagers, and mobile phones strained the available supply in 412. In response, the Pennsylvania Public Utility Commission introduced 878 as an all-number overlay in August 2001. All new number assignments in the overlay region began drawing from both 412 and 878 simultaneously.
How to Dial
Because 878 is an overlay code sharing geography with 412, callers must use 10-digit dialing for all local calls in the region. You dial the full area code plus the seven-digit number even when calling a neighbor. There is no need to dial a leading 1 for local calls, but long-distance calls outside the overlay zone require 1 plus the full 10-digit number. This requirement has been in place since the overlay launched in 2001.
Need a 878 Number for Your Pittsburgh Business?
Businesses operating in the Pittsburgh metro can use a 878 local number to establish a recognizable western Pennsylvania presence. Convirza provisions trackable local numbers in any North American area code, including 878, so you can route calls to any team, office, or location while capturing every interaction. Every call on a Convirza 878 number is recorded, scored for quality, and source-attributed through dynamic number insertion (DNI). You get full visibility into which campaigns, channels, and keywords are driving calls, along with routing controls that let you send calls to the right person every time.
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