Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
  • Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information.
  • If you want to search an entire area code regardless of activity, leave both the next and past days fields set to zero.

NPA: 406 [Rate centres in NPA 406] [Dial plan for NPA 406]

NXX: 533

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-533 A Butte MT BUTTMT18RS1  9636 QWEST CORPORATION 648      
406-533 0 Butte MT   9636 QWEST CORPORATION 648      
406-533 1 Butte MT   9636 QWEST CORPORATION 648      
406-533 2 Butte MT   9636 QWEST CORPORATION 648      
406-533 3 Butte MT   9636 QWEST CORPORATION 648      
406-533 4 Butte MT   624H ONVOY SPECTRUM, LLC 648   2021-07-18   
406-533 5 Butte MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2007-03-22   
406-533 6 Butte MT   9636 QWEST CORPORATION 648      
406-533 7 Butte MT   9636 QWEST CORPORATION 648      
406-533 8 Butte MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2007-07-13   
406-533 9 Butte MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2008-01-22   

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.