Direct answer
Area code 412 serves Pittsburgh and most of Allegheny County, plus small parts of Washington and Westmoreland counties in Pennsylvania. It is in the Eastern Time, and ten-digit dialing is required there.
Facts
| Area code | 412 |
| State | Pennsylvania (PA) |
| Region | Pittsburgh and most of Allegheny County, plus small parts of Washington and Westmoreland counties |
| Time zone | Eastern Time |
| Overlays | 412/724/878 |
| In service since | 1947 (NANPA tool date: 1 January 1947) |
| Dialing rule | Yes — ten-digit dialing is required in this overlay area. |
Areas covered
The 412 footprint covers Pittsburgh and inner-ring Allegheny County suburbs, with small parts of Washington and Westmoreland counties. That list describes the area the code serves today, not the larger territory it may have covered when it was first assigned. Pennsylvania is entirely in the Eastern Time Zone for this footprint. Callers in this area should always dial the full ten-digit number, including the area code, even for a local call.
History
Area code 412 is an original 1947 code that once covered all of south-western Pennsylvania. Area code 724 split off in February 1998 for most of south-western Pennsylvania outside Allegheny County, leaving 412 with the Pittsburgh and Allegheny core. Area code 878 was added as an overlay across both 412 and 724, and NANPA records 878 in service on 17 August 2001, settling an earlier claim of 12 July 2001. The history of when the first 878 prefix was actually assigned in 412 territory is not stated here, because the research draft flagged it as unverified.
Dialing
Dialing rule: Yes — ten-digit dialing is required in this overlay area. The reason is the overlay structure in the facts table above, except where this page states a different reason, as it does for 616. From outside the United States, the country code for the United States is 1, followed by the area code and the local number. This page explains the area code only; it does not identify who owns a number or where a phone is.
Calls and spoofing
A call that shows a familiar area code is not proof of who is calling. Caller ID can be spoofed, so a number that looks local may come from anywhere. Do not share personal or financial details because of the number on the screen, and hang up and call back on a number you trust if a caller asks for money, codes, or account access. This site does not identify callers or phone owners, and it does not list reported spam numbers.
Related codes
724, 878 (overlay complex; 724 is not in 412’s own NANPA row but is corroborated: 878 overlays both, per the NANPA check’s companion-row note).
Frequently asked questions
Where is 412 area code?
Area code 412 is in Pennsylvania, covering Pittsburgh and most of Allegheny County, plus small parts of Washington and Westmoreland counties. It does not cover the whole state.
What time zone is 412 area code?
Area code 412 is in the Eastern Time. Pennsylvania is entirely in the Eastern Time Zone for this footprint.
What area codes overlay 412?
The overlay codes for 412 are 724; 878. The full overlay group is 412/724/878. New numbers in the same territory can carry any code in the group.
Do I need to dial 10 digits for 412?
Yes — ten-digit dialing is required in this overlay area.
When did 412 area code go into service?
Area code 412 has been in service since 1947 (NANPA tool date: 1 January 1947).
Sources
NANPA area code search; Area code 412
Based on a recent search of NANPA and official sources.
This website provides general information about North American area codes, compiled from public sources including NANPA. It is not affiliated with or endorsed by the FCC, NANPA or any telephone carrier. Area code details can change; confirm with your carrier or the official NANPA website. This site does not identify callers or phone owners.