Phone numbers in St. Helena, California
St. Helena has 12 phone prefixes in area code 707.
Biggest holders: AT&T (local phone), MCImetro (Verizon Business), Onvoy. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 17%
- Local phone company 33%
- Internet / business phone carrier 50%
Every prefix in St. Helena
Search the first six digits of a number in this list. If it's here, the number started in St. Helena with the carrier shown. If it isn't, check the California page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 707-200 | Teleport Communications America | Internet / business phone carrier | 2001 |
| 707-244 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 707-286 | Onvoy | Internet / business phone carrier | – |
| 707-302 | Tpx Communications | Internet / business phone carrier | 2001 |
| 707-345 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 707-512 | Onvoy | Internet / business phone carrier | – |
| 707-804 | AT&T Mobility | Mobile carrier | 2019 |
| 707-912 | AT&T Mobility | Mobile carrier | 2021 |
| 707-963 | AT&T (local phone) | Local phone company | – |
| 707-965 | AT&T (local phone) | Local phone company | – |
| 707-967 | AT&T (local phone) | Local phone company | – |
| 707-968 | AT&T (local phone) | 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.