← Area code 573
573-623 phone numbers
Numbers 573-623-0000 to 573-623-9999 are assigned to Onvoy, LLC (rate centre OATES, MO, NANPA abbreviation). 2 of its ten thousand-number blocks are assigned to other carriers (number pooling).
Not assigned to any carrier: 573-623-1xxx, 573-623-3xxx, 573-623-4xxx, 573-623-5xxx, 573-623-8xxx, 573-623-9xxx — calls from these use spoofed caller IDs.
Source: North American Numbering Plan Administrator, Nov 3, 2026. Numbers can move between carriers.