Phone numbers in Interlochen, Michigan
Interlochen has 3 phone prefixes in area code 231.
Biggest holders: CenturyLink / Lumen, AT&T (local phone), Acd Telecom. This is the local calling area (rate center) where those prefixes were first assigned.
- Local phone company 67%
- Phone company 33%
Every prefix in Interlochen
Search the first six digits of a number in this list. If it's here, the number started in Interlochen with the carrier shown. If it isn't, check the Michigan page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 231-212 | CenturyLink / Lumen | Local phone company | 2016 |
| 231-276 | AT&T (local phone) | Local phone company | – |
| 231-774 | Acd Telecom | Phone company | 2005 |
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.