Phone numbers in Geneseo, Illinois
Geneseo has 7 phone prefixes in area code 309.
Biggest holders: Geneseo Tel, T-Mobile (including Sprint), UScellular. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 57%
- Phone company 43%
Every prefix in Geneseo
Search the first six digits of a number in this list. If it's here, the number started in Geneseo with the carrier shown. If it isn't, check the Illinois page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 309-489 | T-Mobile (including Sprint) | Mobile carrier | 2003 |
| 309-502 | T-Mobile (including Sprint) | Mobile carrier | 2003 |
| 309-507 | UScellular | Mobile carrier | – |
| 309-714 | Verizon Wireless | Mobile carrier | 2002 |
| 309-944 | Geneseo Tel | Phone company | – |
| 309-945 | Geneseo Tel | Phone company | – |
| 309-946 | Geneseo Tel | Phone company | 2004 |
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.