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.

Switch: BLTMMDCHDS7

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
443-231 A Essex MD 7421 AT&T LOCAL 238      
443-352 A Pikesville MD 7421 AT&T LOCAL 238      
443-425 A Parkville MD 7421 AT&T LOCAL 238      
443-456 A Edgewood MD 7421 AT&T LOCAL 238      
443-733 A Waterloo MD 7421 AT&T LOCAL 238      
443-760 A Aberdeen MD 7421 AT&T LOCAL 236      
443-883 A Glen Burnie MD 7421 AT&T LOCAL 238      
443-886 A Cockeysville MD 7421 AT&T LOCAL 238      
443-896 A Columbia MD 7421 AT&T LOCAL 238      
443-957 A Baltimore MD 7421 AT&T LOCAL 238      
443-987 A Bel Air MD 7421 AT&T LOCAL 238      

Last updated: Sun, 04 Apr 2021 19:28:27 UTC

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