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: 638

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-638 A Hardin MT CWAGMTXCDS0  2250 PROJECT TEL. CO., INC. 650      
406-638 1 Hardin MT BLNGMTWEIMD  6564 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MT 650      
406-638 2 Hardin MT CWAGMTXCDS0  2250 PROJECT TEL. CO., INC. 650      
406-638 3 Hardin MT CWAGMTXCDS0  2250 PROJECT TEL. CO., INC. 650      
406-638 4 Hardin MT CWAGMTXCDS0  2250 PROJECT TEL. CO., INC. 650      
406-638 5 Hardin MT BLNGMTAS9MD  453F ONVOY, LLC - MT 650      
406-638 6 Hardin MT BLNGMTWEBMD  771G TELEPORT COMMUNICATIONS AMERICA MT - LLC 650      
406-638 7 Hardin MT CWAGMTXCDS0  2250 PROJECT TEL. CO., INC. 650      
406-638 8 Hardin MT BLNGMTAS9MD  453F ONVOY, LLC - MT 650      
406-638 9 Hardin MT CWAGMTXCDS0  2250 PROJECT TEL. CO., INC. 650      

Last updated: Wed, 20 Nov 2024 21:20:06 UTC

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.