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: 943

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-943 A Sidney MT BLNGMTWE2MD  9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650      
406-943 0 Sidney MT   9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650      
406-943 3 Sidney MT   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 650   2016-11-28   
406-943 4 Sidney MT   9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650      
406-943 5 Sidney MT   771G TELEPORT COMMUNICATIONS AMERICA - MT - LLC 650   2015-02-25   
406-943 6 Sidney MT   453F ONVOY, LLC MT 650   2020-11-10   
406-943 7 Sidney MT   508J CENTURYLINK COMMUNICATIONS, LLC 650   2016-08-12   

Last updated: Sat, 31 Oct 2020 19:28:10 UTC

Sponsored by: Execulink Telecom

Like this site? We accept donations via PayPal.