Illinois Area Codes
| State: | Illinois (IL) |
| Area Codes: | 15 |
| Timezone: | Central (CDT) |
| Current Time: | 1:10 AM |
About Illinois Area Codes
Illinois (IL) uses 15 telephone area codes to serve its residents and businesses. With an estimated population of 18,104,498, Illinois is one of the most heavily coded states in the North American Numbering Plan (NANP). The state is primarily in the Central Time Zone (CDT). The current local time in Illinois is 1:10 AM.
The largest cities in Illinois include Chicago (pop. 8,604,203), Rockford (pop. 282,762), Round Lake Beach (pop. 279,381), Peoria (pop. 256,286) and Aurora (pop. 197,757) . Illinois has 102 counties spread across its territory. Each area code in IL covers a geographic region of the state, with some areas using overlay codes that share the same geographic territory as an existing area code.
When calling a Illinois phone number from outside the area code, you must dial the full 10-digit number: the 3-digit area code followed by the 7-digit local number. Many parts of Illinois now require 10-digit dialing even for local calls due to overlay area codes and the nationwide 988 Suicide & Crisis Lifeline implementation.
All Illinois Area Codes
The table below lists every active area code in Illinois, along with the major city served and other cities covered by each code.
| Area Code | Major City | Other Cities |
|---|---|---|
| 217 | Peoria | Champaign, Springfield, Bloomington, Decatur, Danville, Quincy, Jacksonville, Charleston and more |
| 224 | Chicago | Elgin, Arlington Heights, Evanston, Schaumburg, Palatine, Skokie, Des Plaines, Hoffman Estates and more |
| 309 | Peoria | Springfield, Bloomington, Moline, Rock Island, Galesburg, Pekin, East Peoria, East Moline and more |
| 312 | Chicago | Schaumburg, Northbrook, Elk Grove Village, Lisle, Bensenville, La Grange, Wood Dale, Burr Ridge and more |
| 331 | Chicago | Naperville, Elgin, Elmhurst, Buffalo Grove, Northbrook, Elk Grove Village, West Chicago, Lisle and more |
| 447 | Champaign | Springfield, Jacksonville, Mattoon, Macomb, Taylorville, Terre Haute, Indianapolis |
| 464 | Chicago | Schaumburg, Oak Brook |
| 618 | Chicago | Alton, Carbondale, Belleville, Granite City, Edwardsville, Collinsville, Marion, Godfrey and more |
| 630 | Chicago | Aurora, Naperville, Elgin, Bolingbrook, Schaumburg, Wheaton, Hoffman Estates, Downers Grove and more |
| 708 | Chicago | Elgin, Cicero, Arlington Heights, Schaumburg, Orland Park, Tinley Park, Oak Lawn, Oak Park and more |
| 773 | Chicago | Elgin, Cicero, Evanston, Schaumburg, Des Plaines, Buffalo Grove, Park Ridge, Northbrook and more |
| 779 | Chicago | Rockford, Peoria, Joliet, Bloomington, Elgin, Schaumburg, DeKalb, Rock Island and more |
| 815 | Chicago | Rockford, Peoria, Joliet, Bloomington, Elgin, Kankakee, Schaumburg, DeKalb and more |
| 847 | Chicago | Elgin, Waukegan, Arlington Heights, Evanston, Schaumburg, Palatine, Skokie, Des Plaines and more |
| 872 | Chicago | Elgin, Schaumburg, Buffalo Grove, Burr Ridge, Oak Brook |
Largest Cities in Illinois
These are the largest cities in Illinois by population, along with their primary area codes and counties.
| City | Population | County |
|---|---|---|
| Chicago | 8,604,203 | Cook County |
| Rockford | 282,762 | Winnebago County |
| Round Lake Beach | 279,381 | Lake County |
| Peoria | 256,286 | Peoria County |
| Aurora | 197,757 | Kane County |
| Champaign | 159,443 | Champaign County |
| Springfield | 158,509 | Sangamon County |
| Naperville | 148,449 | DuPage County |
| Joliet | 147,344 | Will County |
| Bloomington | 133,846 | McLean County |
Frequently Asked Questions
Illinois is primarily in the Central Time Zone (CDT).
The current local time is 1:10 AM.
The area code covering the most cities in Illinois is 217, which serves Peoria and 256+ other communities.
Yes, most areas in Illinois now require 10-digit dialing (area code + 7-digit number) for all local calls. This requirement was implemented across the United States starting in October 2021 to support the 988 Suicide & Crisis Lifeline. Even if you are calling within the same area code, you need to dial all 10 digits.
To call a Illinois number from within the United States, dial the area code followed by the 7-digit phone number (e.g., 217-XXX-XXXX). From outside the US, dial your country's exit code, then 1 (the US country code), then the full 10-digit number.
Illinois has 102 counties.
The state's total estimated population is 18,104,498, spread across these counties and served by 15 area codes.
Chicago is served by area code
217.
Illinois has 15 area codes in total — see the complete list above.
Illinois at a Glance
- Abbreviation IL
- Area Codes 15
- Population 18,104,498
- Counties 102
- Cities 1,362
- Time Zone Central
- Current Time 1:10 AM
