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.

OCN: 453F ONVOY, LLC - MT

<< 1 2 3 4 5 6 7 8 9 10

NPA-NXX BLOCK Rate Centre Region Switch LATA LIR Eff date Disc date
406-991 8 Marion MT GRFLMTMA7MD  648   2011-03-05   
406-992 A Helena MT   648      

<< 1 2 3 4 5 6 7 8 9 10

Last updated: Sat, 05 Apr 2025 03:03:23 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.