| District of California area codes: 925 | |
|---|---|
| Country | United States |
| State/Province | California |
| Major City | Oakland |
| Time Zone | Pacific |
| Prefix | County | Primary City | Company |
|---|---|---|---|
| 925-577 | Contra Costa | San Ramon, CA | T-mobile Usa |
| 925-579 | Alameda | Livermore, CA | Allegiance Telecom |
| 925-580 | Alameda | Pleasanton, CA | Sprint Spectrum L.p. |
| 925-583 | Alameda | Livermore, CA | U.s. Telepacific Corp. |
| 925-584 | Contra Costa | Antioch, CA | Sprint Spectrum L.p. |
| 925-585 | Contra Costa | Concord, CA | American Messaging Services |
| 925-586 | Contra Costa | Concord, CA | Cellco Partnership DBA Verizon Wireless |
| 925-587 | Contra Costa | San Ramon, CA | Mpower Communications Corp |
| 925-588 | Contra Costa | Walnut Creek, CA | Mpower Communications Corp |
| 925-592 | Contra Costa | Walnut Creek, CA | Mpower Communications Corp |
| 925-594 | Contra Costa | Danville, CA | Metro PCS |
| 925-595 | Contra Costa | Concord, CA | Sprint Spectrum L.p. |
| 925-596 | Alameda | Pleasanton, CA | Cellco Partnership DBA Verizon Wireless |
| 925-597 | Contra Costa | Pittsburg, CA | Cellco Partnership DBA Verizon Wireless |
| 925-598 | Alameda | Pleasanton, CA | Pacific Bell |
| 925-600 | Alameda | Pleasanton, CA | Pacific Bell |
| 925-602 | Contra Costa | Concord, CA | Pacific Bell |
| 925-603 | Contra Costa | Concord, CA | Pacific Bell |
| 925-605 | Alameda | Livermore, CA | Pac - West Telecomm |
| 925-606 | Alameda | Livermore, 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.