Phone numbers in Tres Pinos, California
Tres Pinos has 6 phone prefixes in area code 831.
Biggest holders: Level 3 (Lumen), AT&T (local phone), Verizon Wireless. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 17%
- Local phone company 17%
- Internet / business phone carrier 67%
Every prefix in Tres Pinos
Search the first six digits of a number in this list. If it's here, the number started in Tres Pinos with the carrier shown. If it isn't, check the California page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 831-299 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 831-350 | Level 3 (Lumen) | Internet / business phone carrier | 2006 |
| 831-628 | AT&T (local phone) | Local phone company | – |
| 831-821 | Verizon Wireless | Mobile carrier | – |
| 831-921 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 831-996 | IP Horizon | Internet / business phone carrier | – |
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.