| District of California area codes: 925 | |
|---|---|
| Country | United States |
| State/Province | California |
| Major City | Oakland |
| Time Zone | Pacific |
| Prefix | County | Primary City | Company |
|---|---|---|---|
| 925-444 | Contra Costa | Lafayette, CA | U.s. Telepacific Corp. |
| 925-446 | Contra Costa | Concord, CA | Sprint Spectrum L.p. |
| 925-447 | Alameda | Livermore, CA | Pacific Bell |
| 925-448 | Contra Costa | Walnut Creek, CA | Cellco Partnership DBA Verizon Wireless |
| 925-449 | Alameda | Livermore, CA | Pacific Bell |
| 925-451 | Contra Costa | Walnut Creek, CA | New Cingular Wireless PCS |
| 925-452 | Contra Costa | San Ramon, CA | U.s. Telepacific Corp. |
| 925-453 | Alameda | Livermore, CA | Mcimetro Access Transmission Services LLC |
| 925-454 | Alameda | Livermore, CA | Pacific Bell |
| 925-455 | Alameda | Livermore, CA | Pacific Bell |
| 925-456 | Alameda | Livermore, CA | Pacific Bell |
| 925-457 | Contra Costa | Walnut Creek, CA | Sprint Spectrum L.p. |
| 925-458 | Contra Costa | Pittsburg, CA | Pacific Bell |
| 925-459 | Contra Costa | Concord, CA | Broadwing Communications |
| 925-460 | Alameda | Pleasanton, CA | Pacific Bell |
| 925-461 | Alameda | Pleasanton, CA | Pacific Bell |
| 925-462 | Alameda | Pleasanton, CA | Pacific Bell |
| 925-463 | Alameda | Pleasanton, CA | Pacific Bell |
| 925-464 | Contra Costa | Walnut Creek, CA | Cellco Partnership DBA Verizon Wireless |
| 925-465 | Contra Costa | Walnut Creek, CA | Broadwing Communications |
There are 552 prefixes, In the code area, the major cities are Antioch, CA;Bay Point, CA;Brentwood, CA;Concord, C. The major city is Oakland.