| District of California area codes: 925 | |
|---|---|
| Country | United States |
| State/Province | California |
| Major City | Oakland |
| Time Zone | Pacific |
| Prefix | County | Primary City | Company |
|---|---|---|---|
| 925-304 | Contra Costa | Walnut Creek, CA | Level 3 Communications |
| 925-305 | Contra Costa | Concord, CA | Tw Telecom Of California Lp |
| 925-307 | Contra Costa | San Ramon, CA | Tw Telecom Of California Lp |
| 925-308 | Contra Costa | Brentwood, CA | Tw Telecom Of California Lp |
| 925-309 | Contra Costa | Walnut Creek, CA | Tw Telecom Of California Lp |
| 925-310 | Contra Costa | Lafayette, CA | Tw Telecom Of California Lp |
| 925-312 | Contra Costa | Antioch, CA | Usa Mobility Wireless |
| 925-313 | Contra Costa | Martinez, CA | Pacific Bell |
| 925-314 | Contra Costa | Danville, CA | Pacific Bell |
| 925-315 | Alameda | Livermore, CA | Tw Telecom Of California Lp |
| 925-316 | Contra Costa | Walnut Creek, CA | Level 3 Communications |
| 925-317 | Contra Costa | Walnut Creek, CA | O1 Communications |
| 925-318 | Contra Costa | Walnut Creek, CA | Tw Telecom Of California Lp |
| 925-319 | Alameda | Sunol, CA | T-mobile Usa |
| 925-320 | Contra Costa | Moraga, CA | U.s. Telepacific Corp. |
| 925-321 | Alameda | Livermore, CA | New Cingular Wireless PCS |
| 925-322 | Contra Costa | Walnut Creek, CA | Bandwidth.com Clec |
| 925-323 | Contra Costa | Walnut Creek, CA | New Cingular Wireless PCS |
| 925-324 | Contra Costa | Walnut Creek, CA | Cellco Partnership DBA Verizon Wireless |
| 925-325 | Contra Costa | Pittsburg, CA | T-mobile Usa |
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.