605-540 phone numbers

Numbers 605-540-0000 to 605-540-9999 are assigned to Level 3 Communications, LLC (rate centre NOSIOUX CY, SD, NANPA abbreviation). 4 of its ten thousand-number blocks are assigned to other carriers (number pooling).

Not assigned to any carrier: 605-540-7xxx, 605-540-8xxx, 605-540-9xxx — calls from these use spoofed caller IDs.

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

Reported numbers in 605-540