Illinois area codes

Illinois has 17 active geographic area codes in this directory: 217, 224, 309, 312, 331, 447, 464, 618, 630, 708, 730, 773, 779, 815, 847, 861 and 872.

Start with the first three digits after +1 on the number you want to check. The codes in this directory are associated with places including Decatur, Northbrook, Peoria, Chicago, Naperville, Cicero, Carbondale, La Grange, Rockford, and Schaumburg. The listed places are examples, not a complete map of each code’s boundaries.

NANPA groups these codes in shared numbering complexes: 217 / 447; 224 / 847; 309 / 861; 312 / 872; 331 / 630; 464 / 708; 618 / 730; 773 / 872; 779 / 815; 312 / 773 / 872. Members can serve overlapping areas; being in the same complex does not necessarily mean identical geographic boundaries.

Open the individual area code to check its local dialing rule. For a phone lookup, enter +1 followed by the three-digit area code and the seven-digit number. A state or area code alone is not enough to look up a particular number.

No. An area code describes a number’s assigned region. People can keep numbers after moving, use them while traveling, or place internet-based calls. Caller ID can also be spoofed, so the code does not confirm the caller’s location or identity.