443-399 phone numbers

Numbers 443-399-0000 to 443-399-9999 are assigned to Onvoy, LLC in Dundalk, MD. 6 of its ten thousand-number blocks are assigned to other carriers (number pooling).

Not assigned to any carrier: 443-399-4xxx — calls from these use spoofed caller IDs.

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

Reported numbers in 443-399