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.
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NPA: 406 [Rate centres in NPA 406] [Dial plan for NPA 406]

NXX: 455

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
406-455 A Great Falls MT GRFLMTMADS0  9636 QWEST CORPORATION 648      
406-455 0 Great Falls MT GRFLMTMADS0  9636 QWEST CORPORATION 648      
406-455 1 Great Falls MT GRFLMTMADS0  9636 QWEST CORPORATION 648      
406-455 2 Great Falls MT GRFLMTMADS0  9636 QWEST CORPORATION 648      
406-455 3 Great Falls MT GRFLMTMADS0  9636 QWEST CORPORATION 648      
406-455 4 Great Falls MT GRFLMTMADS0  9636 QWEST CORPORATION 648      
406-455 5 Great Falls MT GRFLMTMADS0  9636 QWEST CORPORATION 648      
406-455 6 Great Falls MT GRFLMTMADS0  9636 QWEST CORPORATION 648      
406-455 8 Great Falls MT GRFLMTMADS0  9636 QWEST CORPORATION 648      
406-455 9 Great Falls MT GRFLMTMADS0  9636 QWEST CORPORATION 648      

Last updated: Sat, 05 Apr 2025 03:03:23 UTC

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