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: 643

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
720-643 A Denver CO DNVTCO56DS8  6118 LEVEL 3 COMMUNICATIONS, LLC - CO 656      
720-643 0 Denver CO   6010 NEW CINGULAR WIRELESS PCS, LLC 656   2015-10-16   
720-643 1 Denver CO   6118 LEVEL 3 COMMUNICATIONS, LLC - CO 656   2015-10-15   
720-643 2 Denver CO   6118 LEVEL 3 COMMUNICATIONS, LLC - CO 656   2015-10-15   
720-643 3 Denver CO   6567 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CO 656   2016-05-31   
720-643 4 Denver CO   6118 LEVEL 3 COMMUNICATIONS, LLC - CO 656   2015-10-15   
720-643 5 Denver CO   318J COMCAST IP PHONE, LLC 656   2015-10-16   
720-643 6 Denver CO   6010 NEW CINGULAR WIRELESS PCS, LLC 656   2015-10-16   
720-643 7 Denver CO   6010 NEW CINGULAR WIRELESS PCS, LLC 656   2015-10-16   
720-643 8 Denver CO   6010 NEW CINGULAR WIRELESS PCS, LLC 656   2015-10-16   
720-643 9 Denver CO   6010 NEW CINGULAR WIRELESS PCS, LLC 656   2015-10-16   

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

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