← Area code 309
309-588 phone numbers
Numbers 309-588-0000 to 309-588-9999 are assigned to Level 3 Communications, LLC in Macomb, IL.
Not assigned to any carrier: 309-588-0xxx, 309-588-1xxx, 309-588-2xxx, 309-588-5xxx, 309-588-6xxx, 309-588-7xxx, 309-588-8xxx, 309-588-9xxx — calls from these use spoofed caller IDs.
Source: North American Numbering Plan Administrator, Nov 3, 2026. Numbers can move between carriers.