| District of California area codes: 925 | |
|---|---|
| Country | United States |
| State/Province | California |
| Major City | Oakland |
| Time Zone | Pacific |
| Prefix | County | Primary City | Company |
|---|---|---|---|
| 925-392 | Contra Costa | Brentwood, CA | Teleport Communications Group - San Francisco |
| 925-394 | Contra Costa | San Ramon, CA | Global Crossing Local Services-ca |
| 925-395 | Contra Costa | Walnut Creek, CA | AT&T Local |
| 925-396 | Alameda | Pleasanton, CA | Pac - West Telecomm |
| 925-397 | Alameda | Pleasanton, CA | Pac - West Telecomm |
| 925-398 | Alameda | Pleasanton, CA | Teleport Communications Group - San Francisco |
| 925-399 | Alameda | Pleasanton, CA | Comcast Phone Of California |
| 925-400 | Alameda | Pleasanton, CA | O1 Communications |
| 925-401 | Alameda | Pleasanton, CA | Allegiance Telecom |
| 925-402 | Contra Costa | Orinda, CA | Allegiance Telecom |
| 925-403 | Contra Costa | Lafayette, CA | Allegiance Telecom |
| 925-404 | Contra Costa | San Ramon, CA | Allegiance Telecom |
| 925-405 | Contra Costa | Concord, CA | Allegiance Telecom |
| 925-406 | Contra Costa | Danville, CA | Allegiance Telecom |
| 925-407 | Contra Costa | Walnut Creek, CA | Allegiance Telecom |
| 925-408 | Contra Costa | Concord, CA | New Cingular Wireless PCS |
| 925-410 | Contra Costa | Martinez, CA | American Messaging Services |
| 925-413 | Contra Costa | San Ramon, CA | New Cingular Wireless PCS |
| 925-415 | Contra Costa | San Ramon, CA | Broadwing Communications |
| 925-416 | Alameda | Pleasanton, CA | Pacific Bell |
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.