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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
406-708 1 Lewistown MT   743G WIDE VOICE, LLC - MT 648   2025-08-12   
406-708 2 Lewistown MT   453F ONVOY, LLC - MT 648   2021-02-11   
406-708 3 Lewistown MT   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 648   2016-09-27   
406-708 4 Lewistown MT   9415 LEVEL 3 COMMUNICATIONS, LLC - MT 648   2005-04-09   
406-708 5 Lewistown MT   453F ONVOY, LLC - MT 648   2021-02-11   
406-708 6 Lewistown MT   453F ONVOY, LLC - MT 648   2006-10-19   
406-708 7 Lewistown MT   508J CENTURYLINK COMMUNICATIONS, LLC 648   2014-05-24   
406-708 8 Lewistown MT   453F ONVOY, LLC - MT 648   2019-10-28   
406-709 A Lakeside MT KLSLMTAZ1MD  792K CHARTER IP ENABLED SERVICES, LLC 648      
406-709 0 Lakeside MT   453F ONVOY, LLC - MT 648   2021-03-07   
406-709 1 Lakeside MT   145J TERRA NOVA TELECOM INC. 648   2025-10-11   
406-709 2 Lakeside MT   792K CHARTER IP ENABLED SERVICES, LLC 648      
406-709 3 Lakeside MT   453F ONVOY, LLC - MT 648   2012-12-14   
406-709 4 Lakeside MT   453F ONVOY, LLC - MT 648   2012-12-14   
406-709 5 Lakeside MT   453F ONVOY, LLC - MT 648   2012-12-14   
406-709 6 Lakeside MT   453F ONVOY, LLC - MT 648   2019-09-15   
406-709 7 Lakeside MT   453F ONVOY, LLC - MT 648   2007-11-17   
406-709 8 Lakeside MT   453F ONVOY, LLC - MT 648   2011-05-14   
406-709 9 Lakeside MT   073H TELNYX LLC 648   2020-08-13   
406-717 A Billings MT BLNGMT937MD  197D VONAGE AMERICA LLC 650      
406-717 0 Billings MT   197D VONAGE AMERICA LLC 650   2018-07-30   
406-717 1 Billings MT   624H ONVOY SPECTRUM, LLC 650   2022-11-12   
406-717 2 Billings MT   624H ONVOY SPECTRUM, LLC 650   2022-11-12   
406-717 3 Billings MT   624H ONVOY SPECTRUM, LLC 650   2022-11-12   
406-717 4 Billings MT   6529 T-MOBILE USA, INC. 650   2022-01-14   
406-717 5 Billings MT   6529 T-MOBILE USA, INC. 650   2022-01-14   
406-717 6 Billings MT   453F ONVOY, LLC - MT 650   2020-04-04   
406-717 7 Billings MT   453F ONVOY, LLC - MT 650   2020-04-04   
406-717 8 Billings MT   6529 T-MOBILE USA, INC. 650   2021-03-12   
406-717 9 Billings MT   6529 T-MOBILE USA, INC. 650   2021-03-12   
406-718 A Darby MT GRFLMTMAPMD  506J TWILIO INTERNATIONAL, INC. 648      
406-718 1 Darby MT   792K CHARTER IP ENABLED SERVICES, LLC 648   2024-09-08   
406-718 4 Darby MT   506J TWILIO INTERNATIONAL, INC. 648   2022-08-28   
406-718 7 Darby MT   453F ONVOY, LLC - MT 648   2021-06-11   
406-718 8 Darby MT   453F ONVOY, LLC - MT 648   2021-06-11   
406-719 A Fromberg MT BLNGMTASMMD  506J TWILIO INTERNATIONAL, INC. 650      
406-719 0 Fromberg MT   073H TELNYX LLC 650   2019-10-21   
406-719 1 Fromberg MT   453F ONVOY, LLC - MT 650   2020-01-05   
406-719 2 Fromberg MT   453F ONVOY, LLC - MT 650   2020-11-10   
406-719 3 Fromberg MT   453F ONVOY, LLC - MT 650   2021-02-11   
406-719 4 Fromberg MT   453F ONVOY, LLC - MT 650   2019-10-20   
406-719 5 Fromberg MT   506J TWILIO INTERNATIONAL, INC. 650   2022-08-28   
406-719 6 Fromberg MT   453F ONVOY, LLC - MT 650   2019-10-20   
406-719 7 Fromberg MT   453F ONVOY, LLC - MT 650   2020-01-05   
406-719 8 Fromberg MT   321J HD CARRIER LLC 650   2020-09-27   
406-719 9 Fromberg MT   453F ONVOY, LLC - MT 650   2021-02-11   
406-720 A Colstrip MT BLNGMTWEIMD  6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 650      
406-720 0 Colstrip MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 650      
406-720 1 Colstrip MT   453F ONVOY, LLC - MT 650   2021-07-05   
406-720 2 Colstrip MT   453F ONVOY, LLC - MT 650   2019-09-15   

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

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