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: 770

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-770 A Great Falls MT GRFLMTMAUMD  318J COMCAST IP PHONE, LLC 648      
406-770 0 Great Falls MT MSSLMTAG5MD  6010 NEW CINGULAR WIRELESS PCS, LLC 648      
406-770 1 Great Falls MT GRFLMTMAUMD  318J COMCAST IP PHONE, LLC 648      
406-770 2 Great Falls MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648      
406-770 3 Great Falls MT   792K CHARTER IP ENABLED SERVICES, LLC 648      
406-770 4 Great Falls MT HLNAMTMAMMD  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 648      
406-770 5 Great Falls MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648      
406-770 6 Great Falls MT MSSLMTMAYMD  771G TELEPORT COMMUNICATIONS AMERICA MT - LLC 648      
406-770 7 Great Falls MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648      
406-770 8 Great Falls MT MSSLMTAG5MD  6010 NEW CINGULAR WIRELESS PCS, LLC 648      
406-770 9 Great Falls MT MSSLMTAG5MD  6010 NEW CINGULAR WIRELESS PCS, LLC 648      

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

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.