667-399 phone numbers

Numbers 667-399-0000 to 667-399-9999 are assigned to Hd Carrier LLC (rate centre UNION BDG, MD, NANPA abbreviation). 6 of its ten thousand-number blocks are assigned to other carriers (number pooling).

Not assigned to any carrier: 667-399-2xxx, 667-399-3xxx — calls from these use spoofed caller IDs.

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

Reported numbers in 667-399