Phone numbers in Cass City, Michigan
Cass City has 5 phone prefixes in area code 989.
Biggest holders: Interactive Services Network, T-Mobile (including Sprint), Onvoy. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 40%
- Local phone company 20%
- Internet / business phone carrier 40%
Every prefix in Cass City
Search the first six digits of a number in this list. If it's here, the number started in Cass City with the carrier shown. If it isn't, check the Michigan page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 989-367 | Interactive Services Network | Internet / business phone carrier | 2002 |
| 989-431 | T-Mobile (including Sprint) | Mobile carrier | 2021 |
| 989-559 | Onvoy | Internet / business phone carrier | 2014 |
| 989-872 | Frontier | Local phone company | – |
| 989-912 | AT&T Mobility | Mobile 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.