Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
  • Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information.
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NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
406-302 A Wolf Creek MT 453F ONVOY, LLC - MT 648      
406-313 A Boulder MT 453F ONVOY, LLC - MT 648      
406-403 A Great Falls MT 453F ONVOY, LLC - MT 648      
406-419 A Victor MT 453F ONVOY, LLC - MT 648   2025-01-13   
406-430 A Helena MT 453F ONVOY, LLC - MT 648      
406-501 A Whitehall MT 453F ONVOY, LLC - MT 648      
406-510 A Missoula MT 453F ONVOY, LLC - MT 648      
406-540 A Missoula MT 453F ONVOY, LLC - MT 648      
406-612 A Swan Lake MT 453F ONVOY, LLC - MT 648      
406-614 A Bigfork MT 453F ONVOY, LLC - MT 648      
406-631 A Elmo MT 453F ONVOY, LLC - MT 648      
406-645 A Deer Lodge MT 453F ONVOY, LLC - MT 648      
406-692 A Yellow Bay MT 453F ONVOY, LLC - MT 648      
406-792 A Butte MT 453F ONVOY, LLC - MT 648      
406-807 A East Glacier Park MT 453F ONVOY, LLC - MT 648      
406-820 A Olney MT 453F ONVOY, LLC - MT 648      
406-836 A Great Falls MT 453F ONVOY, LLC - MT 648      
406-929 A Hungry Horse MT 453F ONVOY, LLC - MT 648      
406-991 A Marion MT 453F ONVOY, LLC - MT 648      

Last updated: Tue, 13 Jan 2026 21:50:02 UTC

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