Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
  • Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information.
  • If you want to search an entire area code regardless of activity, leave both the next and past days fields set to zero.

NPA: 443 [Rate centres in NPA 443] [Dial plan for NPA 443]

NXX: 646

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
443-646 A North Beach MD   829J PAETEC ITEL, LLC 238   2025-04-01   
443-646 1 North Beach MD   829J PAETEC ITEL, LLC 238      
443-646 2 North Beach MD   318J COMCAST IP PHONE, LLC 238   2016-12-02   
443-646 3 North Beach MD   071F BANDWIDTH.COM CLEC, LLC - MD 238   2015-06-04   
443-646 4 North Beach MD   876D ONVOY, LLC - MD 238   2016-03-23   
443-646 5 North Beach MD   318J COMCAST IP PHONE, LLC 238   2014-05-01   
443-646 6 North Beach MD   318J COMCAST IP PHONE, LLC 238   2015-08-05   
443-646 7 North Beach MD   508J CENTURYLINK COMMUNICATIONS, LLC 238   2014-06-12   
443-646 8 North Beach MD   876D ONVOY, LLC - MD 238   2016-03-23   
443-646 9 North Beach MD   073H TELNYX LLC 238   2017-04-26   

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

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.