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.

Culbertson, MT

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
406-514 A BLNGMTMAMMD  6010 NEW CINGULAR WIRELESS PCS, LLC 650      
406-514 0 BLNGMTMAMMD  6010 NEW CINGULAR WIRELESS PCS, LLC 650   2010-12-17   
406-514 1   6010 NEW CINGULAR WIRELESS PCS, LLC 650   2025-02-03   
406-514 2   6010 NEW CINGULAR WIRELESS PCS, LLC 650   2026-04-12   
406-787 A CLSNMTXCRS1  2247 NEMONT TEL COOP INC 650      
406-787 5 CLSNMTXCRS1  2247 NEMONT TEL COOP INC 650      
406-787 6 CLSNMTXCRS1  2247 NEMONT TEL COOP INC 650      
406-787 7 GLSGMTXC1MD  443B SAGEBRUSH CELLULAR, INC. 650      
406-787 8   145J TERRA NOVA TELECOM INC. 650   2025-06-07   
406-790 A BLNGMTMAMMD  6010 NEW CINGULAR WIRELESS PCS, LLC 650      
406-790 0 BLNGMTMAMMD  6010 NEW CINGULAR WIRELESS PCS, LLC 650      
406-790 1   145J TERRA NOVA TELECOM INC. 650   2026-01-04   
406-790 4 BLNGMTMAMMD  6010 NEW CINGULAR WIRELESS PCS, LLC 650   2023-07-31   
406-790 5 BLNGMTMAMMD  6010 NEW CINGULAR WIRELESS PCS, LLC 650   2022-12-21   
406-790 9 BLNGMTMAMMD  6010 NEW CINGULAR WIRELESS PCS, LLC 650   2020-07-26   

Last updated: Tue, 31 Mar 2026 13:56:49 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.