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.
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Switch: DURNCOBSDS0

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
720-537 A Denver CO 330B FASTTRACK COMMUNICATIONS, INC. - CO 656      
970-341 A Olathe CO 330B FASTTRACK COMMUNICATIONS, INC. - CO 656      
970-399 A Delta CO 330B FASTTRACK COMMUNICATIONS, INC. - CO 656      
970-444 A Bayfield CO 330B FASTTRACK COMMUNICATIONS, INC. - CO 656      
970-585 A Pagosa Springs CO 330B FASTTRACK COMMUNICATIONS, INC. - CO 656      
970-828 A Durango CO 330B FASTTRACK COMMUNICATIONS, INC. - CO 656      

Last updated: Tue, 13 Jan 2026 21:50:02 UTC

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