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.


NPA-NXX BLOCK Rate Centre Region Switch LATA LIR Eff date Disc date
406-335 A Sweetgrass MT SNBRMTXCDS0  648      
406-336 A North Cut Bank MT SNBRMTXCDS0  648      
406-337 A Kevin-Oilmont MT SNBRMTXCDS0  648      
406-339 A Ethridge MT SNBRMTXCDS0  648      
406-432 A Devon MT SNBRMTXCDS0  648      
406-937 A Sunburst MT SNBRMTXCDS0  648      

Last updated: Fri, 01 Dec 2023 03:58:46 UTC

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