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: DNVRCOSOFMD

<< 1 2 3 4

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
983-212 7 Denver CO 624H ONVOY SPECTRUM, LLC 656   2024-11-19   
983-212 8 Denver CO 624H ONVOY SPECTRUM, LLC 656   2024-11-19   
983-983 A Longmont CO 624H ONVOY SPECTRUM, LLC 656      
983-983 3 Longmont CO 624H ONVOY SPECTRUM, LLC 656   2023-06-02   
983-983 4 Longmont CO 624H ONVOY SPECTRUM, LLC 656   2023-06-02   
983-983 5 Longmont CO 624H ONVOY SPECTRUM, LLC 656   2023-06-02   

<< 1 2 3 4

Last updated: Tue, 31 Mar 2026 13:56:49 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.