Approved all the way back in 1999 by the Illinois Commerce Commission (ICC), the new 464 area code will be added as a relief plan for Numbering Plan Area 708 which covers the area south of Chicago including these larger communities: Beecher, Berwyn, Chicago Heights, Cicero, Crest Hill, Crete, Hickory Hills, Oak Park, and so on. All calls in the area will be dialed using 1+10 digits with the activation of the new overlay complex 708/464.
- April 24, 2021 – permissive 1+10 digit dialing began under the 988 project
- October 24, 2021 – mandatory 1+10 digit dialing starts (all calls, local or toll between phone numbers in NPA 708 will be dialed using 1+10 digits)
- January 21, 2022 – the new area code 464 enters service
See official NANPA announcement and map of 708/464 overlay complex (PDF document)