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: 406 [Rate centres in NPA 406] [Dial plan for NPA 406]

NXX: 313

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-313 A Boulder MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648      
406-313 0 Boulder MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648      
406-313 1 Boulder MT   792K CHARTER IP ENABLED SERVICES, LLC 648      
406-313 2 Boulder MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648      
406-313 3 Boulder MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648      
406-313 4 Boulder MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648      
406-313 5 Boulder MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648      
406-313 6 Boulder MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648      
406-313 7 Boulder MT HLNAMTMAUMD  508J CENTURYLINK COMMUNICATIONS, LLC 648      
406-313 8 Boulder MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648      
406-313 9 Boulder MT GRFLMTMAHMD  073H TELNYX LLC 648      

Last updated: Wed, 20 Nov 2024 21:20:06 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.