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: 523

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
720-523 A Denver CO BITNCOMADS0  9636 QWEST CORPORATION 656      
720-523 0 Denver CO   6118 LEVEL 3 COMMUNICATIONS, LLC - CO 656   2011-06-11   
720-523 1 Denver CO   078F BANDWIDTH.COM CLEC, LLC - CO 656   2012-02-19   
720-523 2 Denver CO   9636 QWEST CORPORATION 656   2010-07-12   
720-523 3 Denver CO   078F BANDWIDTH.COM CLEC, LLC - CO 656   2010-11-26   
720-523 4 Denver CO   9636 QWEST CORPORATION 656   2010-07-12   
720-523 5 Denver CO   026D ONVOY, LLC - CO 656   2010-11-12   
720-523 6 Denver CO   9636 QWEST CORPORATION 656   2010-07-12   
720-523 7 Denver CO   9636 QWEST CORPORATION 656   2010-07-12   
720-523 8 Denver CO   026D ONVOY, LLC - CO 656   2010-08-14   
720-523 9 Denver CO   278F PEERLESS NETWORK OF COLORADO, LLC - CO 656   2012-02-19   

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

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