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: 302

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-302 A Wolf Creek MT GRFLMTMA7MD  453F ONVOY, LLC - MT 648      
406-302 0 Wolf Creek MT   453F ONVOY, LLC - MT 648   2012-12-17   
406-302 1 Wolf Creek MT   6010 NEW CINGULAR WIRELESS PCS, LLC 648   2015-04-03   
406-302 2 Wolf Creek MT   073H TELNYX LLC 648   2022-05-08   
406-302 3 Wolf Creek MT   9415 LEVEL 3 COMMUNICATIONS, LLC - MT 648   2019-06-28   
406-302 4 Wolf Creek MT   453F ONVOY, LLC - MT 648   2019-09-15   
406-302 5 Wolf Creek MT   453F ONVOY, LLC - MT 648   2019-09-15   
406-302 6 Wolf Creek MT   508J CENTURYLINK COMMUNICATIONS, LLC 648   2014-05-31   
406-302 7 Wolf Creek MT   453F ONVOY, LLC - MT 648   2011-11-28   
406-302 8 Wolf Creek MT   453F ONVOY, LLC - MT 648   2019-10-28   
406-302 9 Wolf Creek MT   453F ONVOY, LLC - MT 648   2020-01-03   

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

Sponsored by: VoIP Much Phone Company

Like this site? We accept donations via PayPal.