Area code 618
Area code 618 is the telephone area code serving southern Illinois, including the cities of Carbondale and Cairo. 618 also serves most of the Metro East region (the east side of the St. Louis area), including Alton, Belleville, East St. Louis, and Edwardsville. (The northern area of Metro East is in area code 217.)
618 was among the original North American area codes created in 1947. In 1954, most of Metro East switched from 217 to 618.
618 is the only one of Illinois' four original area codes never to have been split or overlaid. Under current projections, however, 618 is expected to "exhaust" by 2021. The supply of numbers is further limited because much of 618 is part of the St. Louis LATA; some exchanges in Missouri's 314 and 636 are not available as "618-nxx" numbers.
Periodic proposals have been made for relief of the 618 area code. The most recent proposal has 618 overlaid with the unactivated 730.
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Coordinates: 38°04′N 88°53′W / 38.067°N 88.883°W
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