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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Switch: SDNYMTAORS0

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
406-433 A Sidney MT 7830 MID-RIVERS TELEPHONE COOPERATIVE, INC. 650      
406-488 A Sidney MT 7830 MID-RIVERS TELEPHONE COOPERATIVE, INC. 650      

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

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