Area code 618 is the telephone area code serving the southern part of Illinois. Periodically, proposals have been made for another area code in southern Illinois. Some of these proposals have involved an overlay, with others potentially reducing 618's physical size. The most recent proposal has 618 overlaid with a new area code, 730.
| Illinois area codes: 217, 224, 309, 312, 331, 618, 630, 708, 773, 779, 815, 847, 872 | ||
|---|---|---|
| North: 217 | ||
| West: 314, 636, 573 | Area code 618 | East: 812 |
| South: 573, 270 | ||
| Missouri area codes: 314, 417, 573, 636, 660, 816 | ||
| Kentucky area codes: 270, 502, 606, 859 | ||
| Indiana area codes: 219, 260, 317, 574, 765, 812 | ||