Area Code 618

You can increase your connection rate up to 30% by dialing from a local number.

Local Presence by Tenfold gives you one-click access from your existing phone system to a local number in the US area code 618 and more than 200 others.

Reach out to customers in Collinsville, Alton, Carbondale, Belleville, Mount Vernon and Centralia.

Source: Wikipedia