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: 420C ARMSTRONG TELECOMMUNICATIONS, INC. - MD

NPA-NXX BLOCK Rate Centre Region Switch LATA LIR Eff date Disc date
410-214 2 Rising Sun MD   238   2017-07-07   
410-441 8 Elkton MD   238   2008-08-05   
410-457 8 Darlington MD   238   2008-09-08   
410-656 A North East MD BLTMMDCH47Z  238      
410-656 0 North East MD   238   2008-08-04   
410-692 4 Jarrettsville MD   238   2008-09-08   
410-734 8 Churchville MD   238   2008-09-08   
443-424 0 Cardiff MD   238   2008-09-08   
443-640 6 Bel Air MD   238   2008-09-08   
443-686 3 Fallston MD   238   2008-09-08   
443-731 1 Port Deposit MD   238   2008-08-05   

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.