Phone numbers in Alanson, Michigan
Alanson has 4 phone prefixes in area code 231.
Biggest holders: AT&T Mobility, Interactive Services Network, Onvoy. 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 50%
Every prefix in Alanson
Search the first six digits of a number in this list. If it's here, the number started in Alanson with the carrier shown. If it isn't, check the Michigan page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 231-203 | AT&T Mobility | Mobile carrier | 2004 |
| 231-243 | Interactive Services Network | Internet / business phone carrier | 2004 |
| 231-400 | Onvoy | Internet / business phone carrier | 2019 |
| 231-548 | Brightspeed Of Michigan | 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.