Phone numbers in Fairfield, Illinois
Fairfield has 5 phone prefixes in area code 618.
Biggest holders: Verizon Wireless, Frontier, AT&T Mobility. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 60%
- Local phone company 40%
Every prefix in Fairfield
Search the first six digits of a number in this list. If it's here, the number started in Fairfield with the carrier shown. If it isn't, check the Illinois page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 618-516 | AT&T Mobility | Mobile carrier | 2001 |
| 618-599 | Verizon Wireless | Mobile carrier | – |
| 618-842 | Frontier | Local phone company | – |
| 618-847 | Frontier | Local phone company | – |
| 618-919 | Verizon Wireless | Mobile carrier | 2002 |
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.