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: 879

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-879 A Havre MT MSSLMTAG5MD  6010 NEW CINGULAR WIRELESS PCS, LLC 648      
406-879 0 Havre MT   453F ONVOY, LLC - MT 648   2021-07-05   
406-879 1 Havre MT   453F ONVOY, LLC - MT 648   2021-07-05   
406-879 2 Havre MT   453F ONVOY, LLC - MT 648   2012-12-13   
406-879 3 Havre MT   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 648   2010-01-28   
406-879 4 Havre MT   453F ONVOY, LLC - MT 648   2012-12-13   
406-879 5 Havre MT   453F ONVOY, LLC - MT 648   2012-12-13   
406-879 6 Havre MT   6010 NEW CINGULAR WIRELESS PCS, LLC 648   2010-11-06   
406-879 7 Havre MT   453F ONVOY, LLC - MT 648   2012-12-13   
406-879 9 Havre MT   6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 648   2013-03-29   

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

Sponsored by: VoIP Much Phone Company

Like this site? We accept donations via PayPal.