256-866 phone numbers

Numbers 256-866-0000 to 256-866-9999 are assigned to Onvoy, LLC in Killen, AL. 4 of its ten thousand-number blocks are assigned to other carriers (number pooling).

Not assigned to any carrier: 256-866-1xxx, 256-866-2xxx — calls from these use spoofed caller IDs.

Source: North American Numbering Plan Administrator, Nov 3, 2026. Numbers can move between carriers.

Reported numbers in 256-866