730 Area Code – Belleville, Illinois: Location, Time Zone & History

Few area codes waited as long to go live as 730. The Illinois Commerce Commission reserved it back in October 2000 as a future overlay for area code 618, covering southern Illinois, but implementation was deferred for more than two decades through careful number conservation. Mandatory ten-digit dialing finally arrived across the 618 region on October 24, 2021, driven partly by the new 988 crisis line's conflict with seven-digit dialing, and 730 itself entered service on July 7, 2023 -- a 22-year gap that ranks among the longest in U.S. numbering history.

With 730's launch, every area code in Illinois became an overlay code. The shared 618/730 territory, centered on Belleville, stretches to Carbondale, East St. Louis, Alton, Edwardsville, and Marion, and its economy leans heavily on logistics and defense around Scott Air Force Base -- the region's largest employer -- alongside Southern Illinois University, manufacturing, and agriculture.

The area also carries deep historical weight: Cahokia Mounds, a UNESCO World Heritage Site preserving the largest prehistoric earthworks in the Americas, sits in Collinsville within the 618/730 numbering plan area. The region borders codes 217, 314, 636, 573, 270, and 812.