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: BLNGMTWE6MD

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
406-206 A Billings MT 9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650      
406-213 A Colstrip MT 9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650      
406-530 A Laurel MT 9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650      
406-545 A Billings MT 9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650      
406-551 A Bozeman MT 9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650      
406-630 A Sidney MT 9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650      
406-924 A Belgrade MT 9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650      
406-943 A Sidney MT 9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650      
406-944 A Miles City MT 9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650      
406-946 A Livingston MT 9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650      
406-948 A Glendive MT 9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650      

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

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