| District of Illinois area codes: 618 | |
|---|---|
| Country | United States |
| State/Province | Illinois |
| Major City | Belleville |
| Time Zone | Central (UTC-06:00) |
| Prefix | County | Primary City | Company |
|---|---|---|---|
| 618-346 | Madison | Collinsville, IL | Ameritech Illinois |
| 618-347 | Fayette | Brownstown, IL | Frontier Communications Of Midland |
| 618-348 | Franklin | Benton, IL | Aero Communications, Inc |
| 618-349 | Fayette | St Peter, IL | Citizens Telecom Co Illinois-frontier Citizens -il |
| 618-350 | Jackson | Carbondale, IL | Aero Communications, Inc |
| 618-351 | Jackson | Carbondale, IL | Frontier North |
| 618-352 | Marion | Centralia, IL | Allied Wireless Communications LLC DBA Alltel-il |
| 618-353 | Jackson | Carbondale, IL | Allied Wireless Communications LLC DBA Alltel-il |
| 618-354 | Richland | Olney, IL | Allied Wireless Communications LLC DBA Alltel-il |
| 618-355 | Saint Clair | Belleville, IL | Ameritech Illinois |
| 618-356 | Macoupin | Bunker Hill, IL | Level 3 Communications |
| 618-357 | Perry | Pinckneyville, IL | Frontier North |
| 618-358 | Perry | Pinckneyville, IL | Aero Communications, Inc |
| 618-359 | Marion | Centralia, IL | Allied Wireless Communications LLC DBA Alltel-il |
| 618-360 | Jefferson | Bluford, IL | Ameritech Illinois |
| 618-361 | Madison | Alton, IL | American Messaging (am) |
| 618-362 | Macoupin | Dorchester, IL | Frontier Communications Of Midland |
| 618-363 | Saint Clair | East Saint Louis, IL | Cellco Partnership DBA Verizon Wireless |
| 618-364 | Williamson | Marion, IL | AT&T Local |
| 618-365 | Saint Clair | East Saint Louis, IL | Sbc Internet Services |
There are 692 prefixes, In the code area, the major cities are Alton, IL;Belleville, IL;Carbondale, IL;Collinsvil. The major city is Belleville.