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.

OCN: 4773 XO MARYLAND, LLC

NPA-NXX BLOCK Rate Centre Region Switch LATA LIR Eff date Disc date
443-578 A Cockeysville MD BLTMMDSNDS5  238      
443-578 0 Cockeysville MD BLTMMDSNDS5  238      
443-578 4 Cockeysville MD BLTMMDSNDS5  238      
443-578 5 Cockeysville MD BLTMMDSNDS5  238      
443-853 5 Baltimore MD BLTMMDSNDS5  238   2010-10-20   

Last updated: Sun, 06 Oct 2024 02:51:32 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.