Phone numbers in St. Clair, Michigan
St. Clair has 8 phone prefixes in area code 810.
Biggest holders: AT&T (local phone), Level 3 (Lumen), AT&T Mobility. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 12%
- Local phone company 25%
- Internet / business phone carrier 62%
Every prefix in St. Clair
Search the first six digits of a number in this list. If it's here, the number started in St. Clair with the carrier shown. If it isn't, check the Michigan page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 810-289 | AT&T Mobility | Mobile carrier | 2014 |
| 810-326 | AT&T (local phone) | Local phone company | – |
| 810-328 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 810-329 | AT&T (local phone) | Local phone company | – |
| 810-454 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 810-561 | Interactive Services Network | Internet / business phone carrier | – |
| 810-637 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 810-740 | Level 3 (Lumen) | Internet / business phone carrier | 2001 |
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.