Area code 815 is an area code that covers Northeastern Illinois, except Chicago and its surrounding areas. Area code 815 overlays the area code of 779.
Illinois has area codes of 217, 224, 309, 312, 331, 447, 464, 618, 630, 708, 730, 773, 779, 815, 847, 872.
The following map shows the coverage of 815 area code. The coverage area is shown in green.
Area code map of the entire U.S.