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.
  • If you want to search an entire area code regardless of activity, leave both the next and past days fields set to zero.

Switch: GRFLMTMA69Z

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
406-481 2 Missoula MT 490J DISH WIRELESS, LLC 648   2023-08-21   
406-605 4 Butte MT 490J DISH WIRELESS, LLC 648   2023-12-18   
406-634 5 Helena MT 490J DISH WIRELESS, LLC 648   2023-08-21   
406-736 2 Stockett MT 490J DISH WIRELESS, LLC 648   2024-04-28   
406-858 A Kalispell MT 490J DISH WIRELESS, LLC 648      
406-858 5 Kalispell MT 490J DISH WIRELESS, LLC 648   2023-08-13   
406-866 6 Great Falls MT 490J DISH WIRELESS, LLC 648   2023-08-21   

Last updated: Thu, 16 Oct 2025 03:04:18 UTC

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