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: 225

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-225 A Boulder MT BLDRMTMARS1  9636 QWEST CORPORATION 648      
406-225 0 Boulder MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648   2012-12-10   
406-225 1 Boulder MT GRFLMTMAKMD  624H ONVOY SPECTRUM, LLC 648   2021-11-14   
406-225 3 Boulder MT BLDRMTMARS1  9636 QWEST CORPORATION 648      
406-225 4 Boulder MT BLDRMTMARS1  9636 QWEST CORPORATION 648      
406-225 6 Boulder MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648   2022-10-29   
406-225 7 Boulder MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648   2007-03-19   
406-225 8 Boulder MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648   2022-10-29   
406-225 9 Boulder MT BLDRMTMARS1  9636 QWEST CORPORATION 648      

Last updated: Sun, 26 Jan 2025 15:59:20 UTC

Sponsored by: BeeVox - Whitelabel Reseller Platform

Like this site? We accept donations via PayPal.