← Area code 312
312-331 phone numbers
Numbers 312-331-0000 to 312-331-9999 are assigned to New Cingular Wireless PCS, LLC in Wheeling, IL.
Not assigned to any carrier: 312-331-1xxx, 312-331-2xxx, 312-331-3xxx, 312-331-4xxx, 312-331-5xxx, 312-331-6xxx, 312-331-7xxx, 312-331-8xxx, 312-331-9xxx — calls from these use spoofed caller IDs.
Source: North American Numbering Plan Administrator, Nov 3, 2026. Numbers can move between carriers.