← Area code 313
313-557 phone numbers
Numbers 313-557-0000 to 313-557-9999 are assigned to Mcimetro Access Transmission Services LLC (rate centre DETROITZN1, MI, NANPA abbreviation).
Not assigned to any carrier: 313-557-9xxx — calls from these use spoofed caller IDs.
Source: North American Numbering Plan Administrator, Nov 3, 2026. Numbers can move between carriers.