Phone numbers in Omro, Wisconsin
Omro has 4 phone prefixes in area codes 274, 920.
Biggest holders: T-Mobile (including Sprint), Onvoy, AT&T (local phone). 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 Omro
Search the first six digits of a number in this list. If it's here, the number started in Omro with the carrier shown. If it isn't, check the Wisconsin page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 274-209 | T-Mobile (including Sprint) | Mobile carrier | 2025 |
| 920-658 | Onvoy | Internet / business phone carrier | – |
| 920-685 | AT&T (local phone) | Local phone company | – |
| 920-859 | Charter / Spectrum | Internet / business phone carrier | 2007 |
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.