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: 508

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-508 A Frenchtown MT MSSLMTMA0MD  9415 LEVEL 3 COMMUNICATIONS, LLC - MT 648      
406-508 0 Frenchtown MT   073H TELNYX LLC 648   2020-08-13   
406-508 1 Frenchtown MT   453F ONVOY, LLC - MT 648   2012-12-24   
406-508 2 Frenchtown MT   9415 LEVEL 3 COMMUNICATIONS, LLC - MT 648   2012-04-01   
406-508 3 Frenchtown MT   453F ONVOY, LLC - MT 648   2021-03-07   
406-508 4 Frenchtown MT   453F ONVOY, LLC - MT 648   2021-03-07   
406-508 5 Frenchtown MT   453F ONVOY, LLC - MT 648   2019-09-15   
406-508 6 Frenchtown MT   453F ONVOY, LLC - MT 648   2020-11-08   
406-508 7 Frenchtown MT   508J CENTURYLINK COMMUNICATIONS, LLC 648   2014-05-24   
406-508 8 Frenchtown MT   453F ONVOY, LLC - MT 648   2021-07-05   
406-508 9 Frenchtown MT   453F ONVOY, LLC - MT 648   2021-07-05   

Last updated: Tue, 13 Jan 2026 21:50:02 UTC

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