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: 617

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-617 A Billings MT BLNGMTMAMMD  6010 NEW CINGULAR WIRELESS PCS, LLC 650   2025-02-16   
406-617 0 Billings MT   732J NUSO, LLC 650   2025-02-17   
406-617 1 Billings MT   732J NUSO, LLC 650   2025-02-17   
406-617 7 Billings MT   073H TELNYX LLC 650   2025-02-17   
406-617 8 Billings MT BLNGMTMAMMD  6010 NEW CINGULAR WIRELESS PCS, LLC 650   2025-02-16   
406-617 9 Billings MT BLNGMTMAMMD  6010 NEW CINGULAR WIRELESS PCS, LLC 650   2025-02-16   

Last updated: Sun, 26 Jan 2025 15:59:20 UTC

Sponsored by: LES.NET

Like this site? We accept donations via PayPal.