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: FTCLCOMA7MD

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
720-588 A Denver CO 551G NUSO, LLC 656      
720-588 1 Denver CO 551G NUSO, LLC 656   2012-12-19   
720-667 0 Denver CO 551G NUSO, LLC 656   2018-03-06   
970-305 9 Fort Collins CO 551G NUSO, LLC 656   2013-02-02   

Last updated: Thu, 20 Nov 2025 13:34:34 UTC

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