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: 574

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
443-574 A Ellicott City MD   829J PAETEC ITEL, LLC 238   2025-04-01   
443-574 0 Ellicott City MD   829J PAETEC ITEL, LLC 238      
443-574 1 Ellicott City MD   829J PAETEC ITEL, LLC 238      
443-574 2 Ellicott City MD   829J PAETEC ITEL, LLC 238      
443-574 3 Ellicott City MD   829J PAETEC ITEL, LLC 238      
443-574 4 Ellicott City MD   071F BANDWIDTH.COM CLEC, LLC - MD 238   2010-10-28   
443-574 5 Ellicott City MD   071F BANDWIDTH.COM CLEC, LLC - MD 238   2011-02-26   
443-574 6 Ellicott City MD   071F BANDWIDTH.COM CLEC, LLC - MD 238   2011-08-19   
443-574 7 Ellicott City MD   071F BANDWIDTH.COM CLEC, LLC - MD 238   2011-08-28   
443-574 8 Ellicott City MD   829J PAETEC ITEL, LLC 238   2003-05-25   
443-574 9 Ellicott City MD   829J PAETEC ITEL, LLC 238      

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

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.