406-305 phone numbers

Numbers 406-305-0000 to 406-305-9999 are assigned to New Cingular Wireless PCS, LLC (rate centre WHSLPHRSPG, MT, NANPA abbreviation). 1 of its ten thousand-number blocks are assigned to other carriers (number pooling).

Not assigned to any carrier: 406-305-2xxx, 406-305-3xxx, 406-305-4xxx, 406-305-5xxx, 406-305-6xxx, 406-305-7xxx, 406-305-8xxx, 406-305-9xxx — calls from these use spoofed caller IDs.

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

Reported numbers in 406-305