Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 720 [Rate centres in NPA 720] [Dial plan for NPA 720]

NXX: 573

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
720-573 A Denver CO AURSCOFWDS0  4574 LEVEL 3 TELECOM OF COLORADO, LLC - CO 656      
720-573 0 Denver CO   026D ONVOY, LLC - CO 656   2014-12-04   
720-573 1 Denver CO   026D ONVOY, LLC - CO 656   2014-12-04   
720-573 2 Denver CO   026D ONVOY, LLC - CO 656   2014-12-04   
720-573 3 Denver CO   318J COMCAST IP PHONE, LLC 656   2014-12-02   
720-573 4 Denver CO   318J COMCAST IP PHONE, LLC 656   2015-01-08   
720-573 5 Denver CO   4574 LEVEL 3 TELECOM OF COLORADO, LLC - CO 656   2014-12-01   
720-573 6 Denver CO   318J COMCAST IP PHONE, LLC 656   2015-03-13   
720-573 7 Denver CO   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 656   2015-02-18   
720-573 8 Denver CO   318J COMCAST IP PHONE, LLC 656   2015-10-10   
720-573 9 Denver CO   318J COMCAST IP PHONE, LLC 656   2015-03-13   

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

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