The U.S. state of Illinois is divided into ten distinct geographic numbering plan areas in the North American Numbering Plan (NANP), which are assigned a total of seventeen area codes.

Our area code lookup makes it easy to find area codes in Illinois. Includes area code listings of all Illinois area codes with corresponding cities.

Find the local area code for Chicago, Illinois. Our complete calling resource guide instantly gives you the the Chicago area code and local time to help you make your long distance call to …

List of all area codes in Chicago, IL. Chicago, IL area code map, list, and phone lookup.

This was a controversal spilt where everyone in the City of Chicago changed their area code except "Chicago Zone 01" - an area that covers the loop. This allowed major corporations …

Our area code lookup makes it easy to find area codes in Chicago. Includes area code listings of all Chicago area codes with corresponding cities.

Area codes for Illinois, United States, Illinois dial code information. Country dial and city area codes for Illinois Dial code widgets for Illinois

5 days ago · Illinois - Area code 312 is currently assigned for use in Illinois since January 01, 1947. View all phone prefixes used in area code 312 or other area codes in Illinois.

What is an area code “overlay”? An “overlay” is when more than one area code serves the same geographic area. The City of Chicago has been served by area codes 312 and 773 since …

Area code 312 is a telephone area code in the North American Numbering Plan for the city of Chicago, including downtown, the Chicago Loop, and its immediate environs.