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: 228

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
443-228 A Chase MD   829J PAETEC ITEL, LLC 238   2025-04-01   
443-228 0 Chase MD   829J PAETEC ITEL, LLC 238      
443-228 1 Chase MD   829J PAETEC ITEL, LLC 238      
443-228 3 Chase MD BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238   2021-01-18   
443-228 4 Chase MD BLTMMDCHXNX  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 238   2005-12-12   
443-228 5 Chase MD BLTMMDSN6MD  6119 LEVEL 3 COMMUNICATIONS, LLC - MD 238   2006-05-26   
443-228 6 Chase MD BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238   2010-02-22   
443-228 7 Chase MD   515J IP HORIZON LLC 238   2016-05-31   
443-228 8 Chase MD BLTMMDCH45Z  071F BANDWIDTH.COM CLEC, LLC - MD 238   2008-12-11   
443-228 9 Chase MD BLTMMDCHXUX  624H ONVOY SPECTRUM, LLC 238   2021-02-24   

Last updated: Wed, 18 Jun 2025 02:30:00 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.