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: CHYNWYMAXGX

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
307-310 A Cheyenne WY 624H ONVOY SPECTRUM, LLC 654      
970-780 A South Laramie CO 624H ONVOY SPECTRUM, LLC 654      
970-802 A South Cheyenne CO 624H ONVOY SPECTRUM, LLC 654      

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

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