California · Pacific Time
925 Area Code
Area code 925 is in California, serving eastern Contra Costa County and the Tri-Valley area of eastern Alameda County. It is in the Pacific Time zone.
Last updated October 1, 2026 · Source: NANPA
Where is the 925 area code?
925 is a California area code covering eastern Contra Costa County and the Tri-Valley area of eastern Alameda County. In the wider directory it sits in the West region.
Cities in the 925 area code
- Concord
- Antioch
- Pleasanton
- Livermore
- Walnut Creek
- San Ramon
- Dublin
- Pittsburg
- Brentwood
- Danville
- Martinez
- Oakley
- Lafayette
- Pleasant Hill
Counties served by 925
Contra Costa County and Alameda County.
Dialing 925
Concord, CA is currently served by the single area code 925, with no overlay. Ten-digit dialing (area code + seven-digit number) always works and is increasingly the norm nationwide; some local calls may still connect with seven digits. If a future overlay is added, 10-digit dialing would become mandatory.
From outside the US, dial +1 925 followed by the seven-digit number.
History of the 925 area code
925 went into service on March 14, 1998, created when it was split from 510. It serves Concord and the surrounding part of California. For how codes are created, split, and overlaid, see how area codes work.
Is 925 a scam or spam risk?
925 is a legitimate geographic area code, not a premium or toll line, so a call from it costs you nothing extra. That said, scammers frequently spoof real local area codes to look familiar on caller ID. A genuine 925 number on your screen is no guarantee the caller is in Concord, CA or trustworthy. See spam & scam-risk area codes for how spoofing works and how to respond.
Other California area codes
Explore more
See every code in California, compare codes across the West region, or view all Pacific Time codes. You can also browse the 9XX block or the complete numeric list of US area codes.
New to how this all works? Start with how area codes work, then read up on overlays, 10-digit dialing, and spam & scam-risk codes. To check another number, use the area code lookup tool.
Quick answers
925 area code FAQ
Where is the 925 area code?
The 925 area code is in California, covering eastern Contra Costa County and the Tri-Valley area of eastern Alameda County, in the West region.
What cities are in the 925 area code?
Cities in the 925 area code include Concord, Antioch, Pleasanton, Livermore, Walnut Creek, San Ramon, Dublin, Pittsburg, Brentwood and Danville.
What time zone is 925 in?
925 is in the Pacific Time zone.
When did the 925 area code start?
925 went into service on March 14, 1998.
Do I have to dial 10 digits for 925?
Ten-digit dialing always works, and many areas now require it; some local calls in this area may still connect with seven digits.
Is 925 a toll-free or premium code?
No. 925 is a standard geographic area code, so calling it costs the same as any local or long-distance call on your plan. Toll-free calls use 800, 888, 877, 866, 855, 844 or 833.