Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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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 BLNGMTWE6MD  9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650      
406-943 0 Sidney MT   9415 LEVEL 3 COMMUNICATIONS, LLC - MT 650      
406-943 1 Sidney MT   453F ONVOY, LLC - MT 650   2021-03-07   
406-943 2 Sidney MT   453F ONVOY, LLC - MT 650   2021-03-07   
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   
406-943 8 Sidney MT   453F ONVOY, LLC - MT 650   2021-07-05   
406-943 9 Sidney MT   453F ONVOY, LLC - MT 650   2021-07-05   

Last updated: Thu, 01 Jan 2026 03:59:49 UTC

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