608-666 phone numbers

Numbers 608-666-0000 to 608-666-9999 are assigned to Frontier North Inc. (rate centre LYNDON STA, WI, NANPA abbreviation). 6 of its ten thousand-number blocks are assigned to other carriers (number pooling).

Not assigned to any carrier: 608-666-0xxx, 608-666-1xxx, 608-666-3xxx — calls from these use spoofed caller IDs.

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

Reported numbers in 608-666