Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 406 [Rate centres in NPA 406] [Dial plan for NPA 406]

NXX: 422

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-422 A Helena MT HLNAMTHH5MD  792K CHARTER IP ENABLED SERVICES, LLC 648      
406-422 0 Helena MT HLNAMTHH5MD  792K CHARTER IP ENABLED SERVICES, LLC 648   2006-03-14   
406-422 1 Helena MT HLNAMTHH5MD  792K CHARTER IP ENABLED SERVICES, LLC 648   2007-10-19   
406-422 2 Helena MT HLNAMTMAX1X  6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2007-12-18   
406-422 3 Helena MT HLNAMTMAX1X  6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2007-12-28   
406-422 4 Helena MT HLNAMTHH5MD  792K CHARTER IP ENABLED SERVICES, LLC 648   2008-04-09   
406-422 5 Helena MT HLNAMTHH5MD  792K CHARTER IP ENABLED SERVICES, LLC 648   2005-05-06   
406-422 6 Helena MT HLNAMTMAX1X  6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2008-05-08   
406-422 7 Helena MT HLNAMTMAX1X  6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2008-05-29   
406-422 8 Helena MT HLNAMTMAX1X  6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2008-08-18   
406-422 9 Helena MT HLNAMTMAX1X  6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2008-10-10   

Last updated: Thu, 20 Nov 2025 13:34:34 UTC

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