Area code 309

Area code 309 is a telephone area code in the North American Numbering Plan (NANP) for the west-central part of the U.S. state of Illinois. Cities in the numbering plan area include Bloomington, Canton, East Moline, East Peoria, Galesburg, Kewanee, Macomb, Minonk, Moline, Morton, Normal, Pekin, Peoria, Rock Island, Silvis, and many smaller communities within the western part of central Illinois.

Area codes of Illinois

The area code was created in 1957, and was one of the first area codes not serving an entire state, but having the digit 0 as the second digit of the code. It was the only new area code created in Illinois between the 1947 implementation start of a national numbering plan and the 1989 creation of area code 708.

On October 24, 2021, area code 309 was transitioned to ten-digit dialing, despite not being part of an overlay numbering plan, in which multiple area codes are assigned to a numbering plan area. The area code had telephone numbers assigned for the central office code 988. In 2020, 988 was designated nationwide as a dialing code for the National Suicide Prevention Lifeline, which created a conflict for exchanges that still permitted seven-digit dialing.[1]

NANPA exhaust projections for 309 in 2021 determined an exhaustion date in late 2023.[2] For mitigation, a new all-services distributed overlay was announced with the new area code 861,[3] which is scheduled for operation on February 24, 2023.[4] The earliest date central office codes may be requested is December 20, 2022, but only after all central office codes in area code 309 have been allocated.