Phone numbers in Jefferson, Wisconsin
Jefferson has 7 phone prefixes in area code 920.
Biggest holders: T-Mobile (including Sprint), AT&T (local phone), Teleport Communications America, LLC Wi. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 43%
- Local phone company 29%
- Internet / business phone carrier 14%
- Paging service 14%
Every prefix in Jefferson
Search the first six digits of a number in this list. If it's here, the number started in Jefferson with the carrier shown. If it isn't, check the Wisconsin page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 920-541 | Teleport Communications America, LLC Wi | Internet / business phone carrier | 2002 |
| 920-605 | T-Mobile (including Sprint) | Mobile carrier | – |
| 920-640 | American Messaging Services | Paging service | – |
| 920-650 | AT&T Mobility | Mobile carrier | – |
| 920-674 | AT&T (local phone) | Local phone company | – |
| 920-675 | AT&T (local phone) | Local phone company | – |
| 920-747 | T-Mobile (including Sprint) | Mobile carrier | – |
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.