Chicago, Illinois Area Code

Chicago, IL Area Codes are

312, 773 and 872

Chicago, IL originally utilized area code 312 which was one of the original area codes assigned to Illinois in 1947. In 1996 area code 312 was split to form area code 773. Area code 312 then served the downtown area, or inside "The Loop" and area code 773 served the remainder of the city. On November 7, 2009 area code 872 was put into service. Area code 872 is an overlay of of both 312 and 773.

In Chicago, IL ten digit dialing is necessary in the area code overlays 312 and 872 within the downtown area, and 773 and 872 outside the downtown area. Ten digit dialing (area code + seven digit number) is necessary because two different homes or businesses in the same geographic area can have the same seven digit phone number but each would have a different area code.

Chicago, IL is located in Cook County and observes the Central Time Zone.
View our Times by Area Code tool.

Illinois Area Code Map

Related pages

avon area codecali area codestelephone code nigeriaconnecticut area codes mapsouthside jamaica queens new yorkwhat time zone is south bend indiana onyreka area codearea code 707 zip codehollywood florida area coderussian dailing codelodi area codedestin florida time zonespringfield ohio zip codetime zone for lincoln nearea cod 816031 dialing code011 prefixareacode 916area 704 locationdialing in mexicowhat is 571 area codecleaton kypostal code melvillelogansport indiana time zonewhere is 855 area code canadaindian harbourslada 323boise id time zonemilner bcarea code 860 usausa new jersey phone codezip code for forest grove oregonphx area codeswhat area code is 773828 area code time zonebrentwood phone codeelmira ny zipcodeoswego ny zipcodeburneyville oklahomawhat city is area code 804baroda area codearea code 386 canadaeastern accokeek mdelon area codelarkspur area codelondon ohio area codeladysmith area codeusa area code 704zip code stamford ctarea code 915area code 1617dialing the uk from australiaus country phone code 011gresham area codecalhoun ga area codetexas cell phone area codesthorsby albertawhere is the 714 area code locatedlucas ohio zip codewhat city area code is 321area code 074where is area code 614hattiesburg ms area codesouthern ireland dialing codewhere is the 855 area code locatedgranville area codephone area code 307glendora michiganarea code virginia usawhere is area code 218 locatedsilver spring maryland zip codeshow to dial st maartenarea code 214 is wherearea code 361 timezonearea code 384san mateo timezone760 area code canadawhere is the area code 414 locatedarea code 442 california