Midwest region · Central Time
Illinois Area Codes
All 13 area codes serving Illinois, the cities each one covers, and which are overlays. Illinois is served by 13 area codes in the Central Time zone.
Last updated June 5, 2026
Full list
Every Illinois area code
Illinois is served by 13 area codes in the Central Time zone. 3 of these are overlay codes layered over busy metros; the rest are geographic codes.
| Code | Main city | Type | Status |
|---|---|---|---|
| 217 | Springfield | Geographic | In service |
| 224 | Evanston | Geographic | In service |
| 309 | Peoria | Geographic | In service |
| 312 | Chicago | Geographic | In service |
| 331 | Aurora | Geographic | In service |
| 618 | Belleville | Geographic | In service |
| 630 | Naperville | Geographic | In service |
| 708 | Cicero | Geographic | In service |
| 773 | Chicago | Overlay | In service |
| 779 | Rockford | Overlay | In service |
| 815 | Rockford | Geographic | In service |
| 847 | Schaumburg | Geographic | In service |
| 872 | Chicago | Overlay | In service |
Area codes and dialing in Illinois
Illinois's 13 area codes mix older geographic codes with newer overlays. The busiest metros — around Aurora, Belleville, Chicago — carry the most numbers and rely on overlays, which is why 10-digit dialing is required there. Quieter parts of the state may still use a single code. The original code in the Illinois list is 217 (Springfield).
Whenever a Illinois region runs low on numbers, a new overlay is added on top rather than splitting the map, so existing customers keep their numbers. See 10-digit dialing for what that means in practice, or the newest area codes for upcoming changes.
Cities with multiple area codes
These Illinois metros are served by an overlay of two or more codes, so 10-digit dialing applies: Chicago · Rockford.
Browse Illinois another way
Explore by Midwest region, by time zone, or jump to the city index. You can also see the complete numeric list of every US area code.
Quick answers
Illinois area code FAQ
How many area codes does Illinois have?
Illinois currently has 13 area codes: 217, 224, 309, 312, 331, 618, 630, 708, 773, 779, 815, 847, 872.
What is the main area code for Illinois?
The busiest metro in Illinois is served by the 217 code. Major cities include Aurora, Belleville, Chicago, Cicero, Evanston.
Does Illinois require 10-digit dialing?
Yes, in its overlay metros you must dial all 10 digits. Ten-digit dialing is the national standard.