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.

Switch: GRFLMTMAWMD

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
406-968 A Lewistown MT 321J HD CARRIER LLC 648      
406-968 7 Lewistown MT 321J HD CARRIER LLC 648   2025-07-15   
406-968 8 Lewistown MT 321J HD CARRIER LLC 648   2025-07-15   
406-968 9 Lewistown MT 321J HD CARRIER LLC 648   2025-07-15   

Last updated: Thu, 16 Jul 2026 02:21:55 UTC

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