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: HLRNCOFP1MD

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
720-697 A Denver CO 508J CENTURYLINK COMMUNICATIONS, LLC 656      
720-722 A Denver CO 508J CENTURYLINK COMMUNICATIONS, LLC 656      
720-758 A Denver CO 508J CENTURYLINK COMMUNICATIONS, LLC 656      
720-795 A Denver CO 508J CENTURYLINK COMMUNICATIONS, LLC 656      
970-598 A Platteville CO 508J CENTURYLINK COMMUNICATIONS, LLC 656      
970-866 A La Salle CO 508J CENTURYLINK COMMUNICATIONS, LLC 656      
970-919 A Silverton CO 508J CENTURYLINK COMMUNICATIONS, LLC 656      

Last updated: Thu, 01 Jan 2026 03:59:49 UTC

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