Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 443 [Rate centres in NPA 443] [Dial plan for NPA 443]

NXX: 583

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
443-583 A Columbia MD   829J PAETEC ITEL, LLC 238   2025-04-01   
443-583 0 Columbia MD   876D ONVOY, LLC - MD 238   2016-03-03   
443-583 1 Columbia MD   829J PAETEC ITEL, LLC 238      
443-583 2 Columbia MD   2596 QUANTUM TELECOMMUNICATIONS, INC. - MD 238   2016-01-31   
443-583 3 Columbia MD   071F BANDWIDTH.COM CLEC, LLC - MD 238   2014-03-31   
443-583 4 Columbia MD   071F BANDWIDTH.COM CLEC, LLC - MD 238   2014-03-31   
443-583 5 Columbia MD   876D ONVOY, LLC - MD 238   2014-09-01   
443-583 6 Columbia MD   5562 METROPCS, INC. 238   2015-05-29   
443-583 7 Columbia MD   318J COMCAST IP PHONE, LLC 238   2014-09-16   
443-583 8 Columbia MD   071F BANDWIDTH.COM CLEC, LLC - MD 238   2015-05-14   
443-583 9 Columbia MD   6855 OMNIPOINT COMMUNICATIONS CAP OPERATIONS, LLC 238   2014-11-08   

Last updated: Thu, 01 Jan 2026 03:59:49 UTC

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