Phone numbers in Chillicothe, Illinois
Chillicothe has 4 phone prefixes in area code 309.
Biggest holders: Bandwidth, Frontier, Mediacom Telephony Of Illinois. This is the local calling area (rate center) where those prefixes were first assigned.
- Local phone company 25%
- Internet / business phone carrier 50%
- Phone company 25%
Every prefix in Chillicothe
Search the first six digits of a number in this list. If it's here, the number started in Chillicothe with the carrier shown. If it isn't, check the Illinois page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 309-270 | Bandwidth | Internet / business phone carrier | 2002 |
| 309-274 | Frontier | Local phone company | – |
| 309-603 | Mediacom Telephony Of Illinois | Internet / business phone carrier | 2010 |
| 309-619 | Stratus Networks | Phone company | 2020 |
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.