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: 990

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-990 A Lame Deer MT   6010 NEW CINGULAR WIRELESS PCS, LLC 650      
406-990 0 Lame Deer MT   145J TERRA NOVA TELECOM INC. 650   2025-10-06   
406-990 8 Lame Deer MT BLNGMTMAMMD  6010 NEW CINGULAR WIRELESS PCS, LLC 650   2021-08-27   

Last updated: Thu, 05 Feb 2026 23:41:55 UTC

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