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: GRRNMTXCRS1

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
406-428 A Grass Range MT 2246 MID-RIVERS TEL. COOP., INC. 650      
406-428 2 Grass Range MT 2246 MID-RIVERS TEL. COOP., INC. 650      

Last updated: Fri, 13 May 2022 22:16:13 UTC

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