Phone numbers in St. Charles, Illinois
St. Charles has 35 phone prefixes in area codes 331, 630.
Biggest holders: AT&T Mobility, Verizon Wireless, AT&T (local phone). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 46%
- Local phone company 20%
- Internet / business phone carrier 34%
Every prefix in St. Charles
Search the first six digits of a number in this list. If it's here, the number started in St. Charles with the carrier shown. If it isn't, check the Illinois page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 331-210 | Peerless Network Of Illinois | Internet / business phone carrier | 2012 |
| 331-222 | AT&T Mobility | Mobile carrier | 2008 |
| 331-223 | AT&T Mobility | Mobile carrier | 2008 |
| 331-228 | Windstream (PAETEC) | Internet / business phone carrier | 2011 |
| 331-235 | AT&T Mobility | Mobile carrier | 2017 |
| 331-266 | AT&T Mobility | Mobile carrier | 2020 |
| 331-272 | Onvoy | Internet / business phone carrier | 2021 |
| 331-276 | Verizon Wireless | Mobile carrier | 2014 |
| 331-286 | Verizon Wireless | Mobile carrier | 2022 |
| 331-314 | Verizon Wireless | Mobile carrier | 2023 |
| 331-327 | Verizon Wireless | Mobile carrier | 2024 |
| 331-335 | AT&T Mobility | Mobile carrier | 2024 |
| 331-349 | AT&T Mobility | Mobile carrier | 2026 |
| 331-422 | Level 3 (Lumen) | Internet / business phone carrier | 2008 |
| 331-442 | Verizon Wireless | Mobile carrier | 2008 |
| 331-588 | AT&T Mobility | Mobile carrier | 2010 |
| 331-771 | Onvoy | Internet / business phone carrier | 2016 |
| 331-901 | Bandwidth | Internet / business phone carrier | 2015 |
| 630-338 | AT&T Mobility | Mobile carrier | – |
| 630-377 | AT&T (local phone) | Local phone company | – |
| 630-443 | AT&T (local phone) | Local phone company | – |
| 630-444 | AT&T (local phone) | Local phone company | – |
| 630-485 | Windstream (PAETEC) | Internet / business phone carrier | 2001 |
| 630-488 | Verizon Wireless | Mobile carrier | 2008 |
| 630-513 | AT&T (local phone) | Local phone company | – |
| 630-524 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 630-549 | Teleport Communications America | Internet / business phone carrier | – |
| 630-584 | AT&T (local phone) | Local phone company | – |
| 630-587 | AT&T (local phone) | Local phone company | – |
| 630-659 | Verizon Wireless | Mobile carrier | – |
| 630-715 | AT&T Mobility | Mobile carrier | 2002 |
| 630-762 | AT&T (local phone) | Local phone company | – |
| 630-797 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 630-940 | Windstream (PAETEC) | Internet / business phone carrier | – |
| 630-945 | MCImetro (Verizon Business) | Internet / business phone 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.