Illinois Area Codes: Complete List With Cities Served
Illinois is served by 15 area codes. Several of them are overlays, which means two or more codes share the same territory.
Illinois area code list
| Area code | Main places served |
|---|---|
| 217 | Springfield, Champaign, Decatur and Urbana |
| 224 | Chicago, Palatine, Schaumburg and Evanston |
| 309 | Peoria, Bloomington, Rock Island and Pekin |
| 312 | Chicago and Hinsdale |
| 331 | Aurora, Naperville, Plainfield and Elgin |
| 447 | Springfield, Decatur, Champaign and Urbana |
| 464 | Chicago, Oak Park, Melrose Park and Orland Park |
| 618 | East Saint Louis, Belleville, Carbondale and Edwardsville |
| 630 | Aurora, Carol Stream, Naperville and Plainfield |
| 708 | Chicago, Oak Park, Melrose Park and Chicago Heights |
| 773 | Chicago, Skokie, Oak Park and Des Plaines |
| 779 | Rockford, Joliet, Plainfield and Crystal Lake |
| 815 | Rockford, Joliet, Loves Park and Crystal Lake |
| 847 | Chicago, Schaumburg, Evanston and Palatine |
| 872 | Chicago, Skokie, Oak Park and Des Plaines |
Place names come from ZIP code records linked to each area code, so they show where a code is most common rather than exact boundaries.
Area codes by major city
| City | Area codes |
|---|---|
| Chicago | 224, 312, 464, 708, 773, 847, 872 |
| Rockford | 779, 815 |
| Peoria | 309 |
| Springfield | 217, 447 |
| East Saint Louis | 618 |
| Aurora | 331, 630 |
| Joliet | 779, 815 |
| Belleville | 618 |
| Decatur | 217, 447 |
| Naperville | 331, 630, 779, 815 |
| Schaumburg | 224, 331, 630, 847 |
| Bloomington | 309 |
| Carbondale | 618 |
| Champaign | 217, 447 |
| Elgin | 224, 331, 630, 847 |
How to format a Illinois phone number
US numbers have ten digits: the area code, a three-digit exchange and a four-digit line number. A Illinois number is written as (217) 555-0123 for display, or +12175550123 in E.164 format for storage.
Safe numbers for testing
The range 555-0100 to 555-0199 is reserved for fictional use in every area code. Our generator combines these with real local area codes, so test data looks right without reaching a real person.
Why overlays matter for your forms
With overlays, you cannot guess a city from its area code alone, and people who move keep their numbers. Use area codes for display and formatting, not for location checks.
Create realistic Illinois addresses for testing, with real cities, counties and ZIP codes.
Generate Illinois addresses