Published: January 21, 2022
The northwestern area of Illinois currently served by NPA 309 will soon join the growing number of US and Canadian locations using two or more overlaying area codes for telephone and other communications services. The new 861 Numbering Plan Area will be activated beginning February 24, 2023 and will serve the same geographic area covered at the moment by area code 309 alone. Among the larger communities within this NPA's borders are Bloomington, Macomb, Moline, Normal and Peoria.
Area code 309 is among the 80+ Numbering Plan Areas using central office code 988 and where local 10 digit dialing was implemented last year in November, so there will no change in the dialing plan currently used by residents of this part of Illinois: 10 (1+10 where permitted) digits for local calls and 1+10 digits for toll calls.
See official planning letter announcing the new overlaying area (PDF document).