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← Area code 423

423-340 phone numbers

Numbers 423-340-0000 to 423-340-9999 are assigned to T-Mobile USA in Bristol, TN. 4 of its ten thousand-number blocks are assigned to other carriers (number pooling).

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

Reported numbers in 423-340