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: DNVRCOMA37Z

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
720-721 A Denver CO 507J THE VOICE APPLICATION NETWORK, LLC 656      
720-721 1 Denver CO 507J THE VOICE APPLICATION NETWORK, LLC 656   2016-06-12   

Last updated: Sun, 26 Jan 2025 15:59:20 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.