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: 639

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
443-639 A Hampstead MD   829J PAETEC ITEL, LLC 238   2025-04-01   
443-639 0 Hampstead MD   073H TELNYX LLC 238   2017-04-26   
443-639 1 Hampstead MD   876D ONVOY, LLC - MD 238   2024-05-23   
443-639 2 Hampstead MD   318J COMCAST IP PHONE, LLC 238   2017-07-07   
443-639 3 Hampstead MD   829J PAETEC ITEL, LLC 238      
443-639 4 Hampstead MD   071F BANDWIDTH.COM CLEC, LLC - MD 238   2015-06-04   
443-639 5 Hampstead MD   318J COMCAST IP PHONE, LLC 238   2015-04-02   
443-639 6 Hampstead MD   8697 BALTIMORE-WASHINGTON TELEPHONE (BWT) 238   2015-06-13   
443-639 7 Hampstead MD   508J CENTURYLINK COMMUNICATIONS, LLC 238   2014-06-12   
443-639 8 Hampstead MD   876D ONVOY, LLC - MD 238   2014-10-21   
443-639 9 Hampstead MD   876D ONVOY, LLC - MD 238   2014-10-21   

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

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