State directory / Illinois
US number directory / Illinois
Illinois
area codes
The earliest listed Illinois codes are 217, 312, 618, 815, in service since 1947; the state now has 17 geographic codes.
17geographic area codes
in this reference
in this reference
Earliest listed217, 312, 618, 815 · 1947
Standard timeCT
Overlays in this stateYes — see code notes
Major city starting points
Springfield (capital): 217, 447; Chicago (largest city in state reference): 224, 312, 331, 464, 630, 773, 779, 815, 847, 872.
| City | Reference role | Codes to check |
|---|---|---|
| Springfield | Capital | 217, 447 |
| Chicago | Largest city in state reference | 224, 312, 331, 464, 630, 773, 779, 815, 847, 872 |
City reference · 2026-10-25
Codes, cities & coverage
Illinois's active territorial overlay complexes are 217/447; 224/847; 309/861; 312/872; 331/630; 464/708; 618/730; 773/872; 779/815.
| Code | Region / major cities named in the reference | Introduced | Active overlay complexes |
|---|---|---|---|
| 217 | Central Illinois ( Springfield , Champaign , Decatur , Urbana , Lincoln ) | 01-Jan-1947 | 217/447 |
| 224 | Illinois (North and northwest suburbs of Chicago) | 05-Jan-2002 | 224/847 |
| 309 | Illinois ( Peoria , Bloomington , Moline , Rock Island , Galesburg ; west-central Illinois) | 01-Jan-1957 | 309/861 |
| 312 | Illinois (downtown Chicago ) | 01-Jan-1947 | 312/872 |
| 331 | Illinois (Aurora, Naperville, Oswego; western suburbs of Chicago ) | 07-Oct-2007 | 331/630 |
| 447 | Illinois ( Springfield , Champaign , Decatur, Urbana, Lincoln, and parts of central Illinois) | 27-Mar-2021 | 217/447 |
| 464 | Illinois (western and southern portions of suburban Cook County and far eastern sections of Will County and southern and near western suburbs of Chicago ) | 21-Jan-2022 | 464/708 |
| 618 | Illinois ( Carbondale , Alton, Belleville, Cahokia, Centralia, Edwardsville, Marion, Metropolis , Vandalia , and most of southern Illinois ) | 01-Jan-1947 | 618/730 |
| 630 | Illinois (western suburbs of Chicago, including DuPage , central and southern Kane , northern Kendall , far northern Will , and small portions of Cook counties) | 03-Aug-1996 | 331/630 |
| 708 | Illinois (western and southern portions of suburban Cook County and far eastern sections of Will County ) | 11-Nov-1989 | 464/708 |
| 730 | Illinois ( Carbondale , Alton, Belleville, Cahokia, Centralia, Edwardsville, Marion, Metropolis , Vandalia , and most of southern Illinois ) | 07-Jul-2023 | 618/730 |
| 773 | Illinois (City of Chicago , excluding downtown) | 12-Oct-1996 | 773/872 |
| 779 | Illinois (much of northern Illinois outside Chicago and its immediate surrounding suburbs: Rockford and its suburbs, Belvidere, La Salle, Peru, DeKalb, Sycamore, Freeport, Dixon, Sterling, Rock Falls, Ottawa, Morris, Princeton, Mendota, Rochelle, Sandwich, Streator, Pontiac, Kankakee, and some outlying Chicago suburbs such as Harvard, McHenry, Crystal Lake, Woodstock, Plainfield, Joliet, Romeoville, Lockport, New Lenox, Frankfort, Minooka, Channahon, and Shorewood) | 17-Mar-2007 | 779/815 |
| 815 | Illinois (much of northern Illinois outside Chicago and its immediate surrounding suburbs: Rockford and its suburbs, Belvidere, La Salle, Peru, DeKalb , Sycamore, Freeport, Dixon, Sterling, Rock Falls, Ottawa, Morris, Princeton, Mendota, Rochelle, Sandwich, Streator, Pontiac, Kankakee, and some outlying Chicago suburbs such as Harvard, McHenry, Crystal Lake, Woodstock, Plainfield, Joliet, Romeoville, Lockport, New Lenox, Frankfort, Minooka, Channahon, and Shorewood) | 01-Jan-1947 | 779/815 |
| 847 | Illinois (North and northwest suburbs of Chicago, including Lake , northern Cook , northern Kane , and extreme southeastern McHenry Counties ; includes Evanston, Skokie, Niles, Park Ridge, Des Plaines, Mount Prospect, Arlington Heights, Palatine, Wheeling, Buffalo Grove, Barrington, Elk Grove Village, Schaumburg, Hoffman Estates, Elgin, Carpentersville, Algonquin, Lake in the Hills, Huntley, Hampshire, Cary, Lake Zurich, Fox Lake, Round Lake Beach, Antioch, Gurnee, Waukegan, Zion, Lake Forest, Vernon Hills, Libertyville, Mundelein, Northbrook, Glenview, Deerfield, Highland Park, Wilmette, Winnetka) | 20-Jan-1996 | 224/847 |
| 861 | Illinois ( Peoria , Bloomington , Moline , Rock Island , Galesburg ; west-central Illinois) | 24-Feb-2023 | 309/861 |
| 872 | Illinois ( Chicago ) | 07-Nov-2009 | 312/872; 773/872 |
NANPA dates & overlays · 2026-10-25
Wikipedia geography · 2026-10-25 · CC BY-SA 4.0
Time zones
Illinois spans 1 standard-time offset in the state reference: CT.
| Standard offset | Region | Daylight saving |
|---|---|---|
| UTC−06:00 CT | Central | Yes |