← Area code 773
773-421 phone numbers
Numbers 773-421-0000 to 773-421-9999 are assigned to Verizon Wireless (rate centre CHICGOZN01, IL, NANPA abbreviation).
Not assigned to any carrier: 773-421-0xxx, 773-421-1xxx, 773-421-2xxx, 773-421-3xxx, 773-421-4xxx, 773-421-5xxx, 773-421-6xxx, 773-421-7xxx, 773-421-8xxx, 773-421-9xxx — calls from these use spoofed caller IDs.
Source: North American Numbering Plan Administrator, Nov 3, 2026. Numbers can move between carriers.