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: 313

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-313 A Boulder MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648      
406-313 0 Boulder MT   453F ONVOY, LLC - MT 648   2013-01-17   
406-313 1 Boulder MT   792K CHARTER IP ENABLED SERVICES, LLC 648   2019-06-14   
406-313 2 Boulder MT   453F ONVOY, LLC - MT 648   2020-04-04   
406-313 3 Boulder MT   453F ONVOY, LLC - MT 648   2019-10-28   
406-313 4 Boulder MT   453F ONVOY, LLC - MT 648   2020-01-03   
406-313 5 Boulder MT   453F ONVOY, LLC - MT 648   2020-02-23   
406-313 6 Boulder MT   453F ONVOY, LLC - MT 648   2013-01-17   
406-313 7 Boulder MT   508J CENTURYLINK COMMUNICATIONS, LLC 648   2014-05-24   
406-313 8 Boulder MT   453F ONVOY, LLC - MT 648   2020-04-04   
406-313 9 Boulder MT   073H TELNYX LLC 648   2020-08-07   

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

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