North American Area Code 317 serves the Indianapolis area in central Indiana. Originally, 317 covered the entire area between Area Code 219 in Northern Indiana and Area Code 812 in southern Indiana. However, population growth in and around Indianapolis, combined with the explosion of FAX and cellular lines, necessitated a split. Beginning on February 1, 1997 (with mandatory dialing beginning on June 28), Area Code 317 was split between 317 for the Indianapolis area and immediate surroundings and Area Code 765 for the rest of Central Indiana. Area Code 317 now serves most of the Indianapolis Metropolitan Service Area, including all of Marion County (the City of Indianapolis) and portions of Hancock, Shelby, Johnson, Morgan, Hendricks, Boone, and Hamilton Counties surrounding Indianapolis. ^[1]

North, East, and West: Area Code 765 South: Area code 812 North American area code 812 includes cities and regions in southern Indiana (Bedford, Bloomington, Columbus, Evansville, Jasper, Jeffersonville, Madison, Mount Vernon, New Albany, Princeton, Seymour, Terre Haute, and Vincennes, among others). ...

References