Local Calling Guide

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

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NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-323 7 Roundup MT   2246 MID-RIVERS TEL. COOP., INC. 650      
406-323 8 Roundup MT   2246 MID-RIVERS TEL. COOP., INC. 650      
406-323 9 Roundup MT   2246 MID-RIVERS TEL. COOP., INC. 650      
406-324 A Helena MT HLNAMTMADS0  9636 QWEST CORPORATION 648      
406-324 0 Helena MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2024-06-22   
406-324 1 Helena MT   9636 QWEST CORPORATION 648      
406-324 2 Helena MT   9636 QWEST CORPORATION 648      
406-324 3 Helena MT   9636 QWEST CORPORATION 648      
406-324 4 Helena MT   9636 QWEST CORPORATION 648      
406-324 5 Helena MT   9636 QWEST CORPORATION 648      
406-324 6 Helena MT   9636 QWEST CORPORATION 648      
406-324 7 Helena MT   453F ONVOY, LLC - MT 648   2006-05-27   
406-324 8 Helena MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2025-02-12   
406-324 9 Helena MT   073H TELNYX LLC 648   2020-08-13   
406-325 A Billings MT BLNGMTMAX6X  732J NUSO, LLC 650      
406-325 0 Billings MT   939H COMMIO, LLC 650   2024-03-03   
406-325 1 Billings MT   732J NUSO, LLC 650   2022-09-29   
406-325 2 Billings MT   939H COMMIO, LLC 650   2024-03-03   
406-325 3 Billings MT   939H COMMIO, LLC 650   2024-03-03   
406-325 4 Billings MT   4222 ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM 650      
406-325 5 Billings MT   6529 T-MOBILE USA, INC. 650   2025-08-07   
406-325 6 Billings MT   453F ONVOY, LLC - MT 650   2015-12-10   
406-325 7 Billings MT   994E BANDWIDTH.COM CLEC, LLC - MT 650   2016-07-16   
406-325 8 Billings MT   4222 ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM 650      
406-325 9 Billings MT   939H COMMIO, LLC 650   2024-03-03   
406-326 A Reedpoint MT BGTMMTXCDS0  2257 TRIANGLE TEL. COOP. ASSN., INC. 650      
406-327 A Missoula MT MSSLMTMADS0  9636 QWEST CORPORATION 648      
406-328 A Absarokee MT ABSRMTXCDS0  2250 PROJECT TEL. CO., INC. 650      
406-328 3 Absarokee MT   9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650   2023-03-29   
406-328 4 Absarokee MT   2250 PROJECT TEL. CO., INC. 650      
406-328 6 Absarokee MT   2250 PROJECT TEL. CO., INC. 650      
406-328 7 Absarokee MT   2250 PROJECT TEL. CO., INC. 650      
406-328 8 Absarokee MT   2250 PROJECT TEL. CO., INC. 650      
406-328 9 Absarokee MT   2250 PROJECT TEL. CO., INC. 650      
406-329 A Missoula MT MSSLMTMADS0  9636 QWEST CORPORATION 648      
406-330 A Clinton MT MSSLMTEH4MD  792K CHARTER IP ENABLED SERVICES, LLC 648      
406-330 0 Clinton MT   6529 T-MOBILE USA, INC. 648   2024-09-23   
406-330 2 Clinton MT   792K CHARTER IP ENABLED SERVICES, LLC 648   2006-06-03   
406-330 3 Clinton MT   145J TERRA NOVA TELECOM INC. 648   2025-10-06   
406-331 A Roundup MT BLNGMTWEIMD  6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 650      
406-331 0 Roundup MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 650      
406-331 1 Roundup MT   145J TERRA NOVA TELECOM INC. 650   2025-08-29   
406-332 A Pablo MT MSSLMTXCDS0  2235 BLACKFOOT TEL. COOP., INC. 648      
406-332 1 Pablo MT   792K CHARTER IP ENABLED SERVICES, LLC 648   2024-03-31   
406-332 2 Pablo MT   145J TERRA NOVA TELECOM INC. 648   2025-10-09   
406-332 9 Pablo MT   2235 BLACKFOOT TEL. COOP., INC. 648      
406-333 A Livingston MT PRAYMTMARS1  9636 QWEST CORPORATION 650      
406-333 0 Livingston MT   9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650   2004-11-13   
406-333 1 Livingston MT   994E BANDWIDTH.COM CLEC, LLC - MT 650   2012-09-09   
406-333 2 Livingston MT   792K CHARTER IP ENABLED SERVICES, LLC 650   2006-05-17   

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

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