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: 643

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-643 A North Parkman MT CHYNWYMAX2X  453F ONVOY, LLC - MT 654      
406-643 0 North Parkman MT   453F ONVOY, LLC - MT 654   2012-12-17   
406-643 1 North Parkman MT   073H TELNYX LLC 654   2018-07-25   
406-643 2 North Parkman MT   453F ONVOY, LLC - MT 654   2021-02-11   
406-643 3 North Parkman MT   453F ONVOY, LLC - MT 654   2021-02-11   
406-643 4 North Parkman MT   453F ONVOY, LLC - MT 654   2020-11-10   
406-643 5 North Parkman MT   453F ONVOY, LLC - MT 654   2021-07-05   
406-643 6 North Parkman MT   453F ONVOY, LLC - MT 654   2019-09-15   
406-643 7 North Parkman MT   453F ONVOY, LLC - MT 654   2007-07-18   
406-643 8 North Parkman MT   624H ONVOY SPECTRUM, LLC 654   2021-07-19   
406-643 9 North Parkman MT   624H ONVOY SPECTRUM, LLC 654   2021-11-14   

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

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