Illinois Area Code Information

Illinois Area Codes


Illinois Area Code Overlays
(847 and 224) - (815 and 779)
(630 and 331) - (312 and 872)
(773 and 872)


Illinois is currently using thirteen area codes. Illinois currently has three area codes, 447,464, and 730, which are assigned to provide numbering relief but are not yet in service. Illinois utilizes five area code overlay plans, often called an overlay complex.

Illinois originally had four area codes, 217,312,618 and 815, when the numbering system was established in 1947. It was not until ten years later in 1957 that Illinois experienced sufficient growth in population and telephone use to need an additional area code. In 1957 area code 309 was created by a split of area codes 217 and 815. These five area codes were sufficient until 1989.

Changes and History of Illinois Area Codes:

01/01/1947
Area code 217 was put into service. In 1957 area code 217 was split, along with a portion of area code 815, to form part of area code 309.

01/01/1947
Area code 312 was put into service. In 1989 Area code 312 was split to form area code 708. In 1996 area code 312 was split again to form area code 773. In 2009 area code 312 was overlaid with area code 872.

Illinois Area Code Map

Area code 618 was put into service.

01/01/1947
Area code 815 was put into service. In 1957 area code 815 was split, along with a portion of area code 217, to form area code 309. In 2007 area code 815 was overlaid with area code 779.

01/01/1957
Area code 309 was put into service. Area code 309 was created from splits of area codes 217 and 815.

11/11/1989
Area code 708 was put into service. Then in 1996 portions of area code 708 were split to form area codes 847 and 630. Area code 464, which is not yet in service, has been proposed as an overlay of area code 708.

01/20/1996
Area code 847 was put into service. Area code 847 created from a split of area code 708. In 1998 area code 847 was overlaid with area code 224 but it was not put into service until 2002.

08/03/1996
Area code 630 was put into service. Area code 630 was created from a split of area code 708. In 2007 area code 630 was overlaid with area code 331.

10/12/1996
Area code 773 was put into service. Area code 773 was created from a split of area code 312. In 2009 area code 773 was overlaid with area code 872.

01/05/2002
Area code 224 was put into service. Area code 224 is an overlay  of area code 847.

03/17/2007
Area code 779 was put into service. Area code 779 is an overlay of area code 815.

10/07/2007
Area code 331 was put into service. Area code 331 is an overlay of area code 630.

11/07/2009
Area code 872 was put into service. Area code 872 is an overlay of area codes 312 and 773.

not in service
Area code 447 proposed. Area code 447 is proposed as an overlay of area code 217 but is not yet in service.

not in service
Area code 464 proposed. Area code 464 is proposed as an overlay of area code 708 but is not yet in service.

not in service
Area code 730 proposed. Area code 730 is proposed as an overlay of area code 618 but is not yet in service.