Phone numbers in San Joaquin, California
San Joaquin has 7 phone prefixes in area code 559.
Biggest holders: Frontier, Comcast, MetroPCS (T-Mobile). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 29%
- Local phone company 43%
- Internet / business phone carrier 29%
Every prefix in San Joaquin
Search the first six digits of a number in this list. If it's here, the number started in San Joaquin with the carrier shown. If it isn't, check the California page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 559-210 | Comcast | Internet / business phone carrier | – |
| 559-364 | MetroPCS (T-Mobile) | Mobile carrier | – |
| 559-525 | Peerless Network Of California | Internet / business phone carrier | – |
| 559-630 | AT&T Mobility | Mobile carrier | – |
| 559-693 | Frontier | Local phone company | – |
| 559-698 | Frontier | Local phone company | – |
| 559-829 | Frontier | Local phone company | – |
Most prefixes are pooled: the 10,000 numbers in each are handed out in blocks of 1,000 to different carriers, and people can also take their numbers to another carrier. So the carrier shown is where the prefix started, not a guarantee about any one number. Source: NANPA central office code records, 2026-10-10.