Phone numbers in Sunfield, Michigan
Sunfield has 4 phone prefixes in area code 517.
Biggest holders: AT&T Mobility, Onvoy, Brightspeed Of Central Michigan. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 25%
- Local phone company 25%
- Internet / business phone carrier 25%
- Phone company 25%
Every prefix in Sunfield
Search the first six digits of a number in this list. If it's here, the number started in Sunfield with the carrier shown. If it isn't, check the Michigan page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 517-288 | AT&T Mobility | Mobile carrier | 2004 |
| 517-500 | Onvoy | Internet / business phone carrier | 2018 |
| 517-566 | Brightspeed Of Central Michigan | Local phone company | – |
| 517-597 | Acd Telecom | Phone company | 2002 |
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.