Phone numbers in Lake Mills, Iowa
Lake Mills has 3 phone prefixes in area code 641.
Biggest holders: Winnebago Coop. Tel. Assn, T-Mobile (including Sprint). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 33%
- Phone company 67%
Every prefix in Lake Mills
Search the first six digits of a number in this list. If it's here, the number started in Lake Mills with the carrier shown. If it isn't, check the Iowa page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 641-591 | Winnebago Coop. Tel. Assn | Phone company | – |
| 641-592 | Winnebago Coop. Tel. Assn | Phone company | – |
| 641-909 | T-Mobile (including Sprint) | Mobile carrier | 2006 |
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.