Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 303 [Rate centres in NPA 303] [Dial plan for NPA 303]

NXX: 350

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
303-350 A Denver CO DNVRCOMD4MD  6010 NEW CINGULAR WIRELESS PCS, LLC 656      
303-350 0 Denver CO   6010 NEW CINGULAR WIRELESS PCS, LLC 656      
303-350 1 Denver CO   026D ONVOY, LLC - CO 656   2004-10-30   
303-350 2 Denver CO   026D ONVOY, LLC - CO 656   2004-10-30   
303-350 3 Denver CO   026D ONVOY, LLC - CO 656   2005-01-01   
303-350 4 Denver CO   3467 ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM 656   2004-05-07   
303-350 5 Denver CO   3467 ELECTRIC LIGHTWAVE LLC DBA ALLSTREAM 656   2004-07-08   
303-350 6 Denver CO   6529 T-MOBILE USA, INC. 656   2004-12-12   
303-350 7 Denver CO   6529 T-MOBILE USA, INC. 656   2005-12-17   
303-350 8 Denver CO   6529 T-MOBILE USA, INC. 656   2005-12-17   
303-350 9 Denver CO   6010 NEW CINGULAR WIRELESS PCS, LLC 656   2006-02-26   

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

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