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: 321

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-321 A Columbus MT BLNGMTMAMMD  6010 NEW CINGULAR WIRELESS PCS, LLC 650      
406-321 0 Columbus MT   6010 NEW CINGULAR WIRELESS PCS, LLC 650      
406-321 1 Columbus MT   6010 NEW CINGULAR WIRELESS PCS, LLC 650      
406-321 2 Columbus MT   6010 NEW CINGULAR WIRELESS PCS, LLC 650      
406-321 3 Columbus MT   6010 NEW CINGULAR WIRELESS PCS, LLC 650      
406-321 4 Columbus MT   6010 NEW CINGULAR WIRELESS PCS, LLC 650      
406-321 5 Columbus MT   453F ONVOY, LLC - MT 650   2021-02-11   
406-321 6 Columbus MT   453F ONVOY, LLC - MT 650   2021-02-11   
406-321 7 Columbus MT   145J TERRA NOVA TELECOM INC. 650   2021-09-28   
406-321 8 Columbus MT   588H AIRUS, INC. - MT 650   2020-07-20   
406-321 9 Columbus MT   6010 NEW CINGULAR WIRELESS PCS, LLC 650      

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

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