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: BLTMMDSN3MD

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
240-972 A Laurel (Baltimore LATA) MD 8697 BALTIMORE-WASHINGTON TELEPHONE (BWT) 238      
410-915 A Baltimore MD 8697 BALTIMORE-WASHINGTON TELEPHONE (BWT) 238      
410-999 A Glen Burnie MD 8697 BALTIMORE-WASHINGTON TELEPHONE (BWT) 238      
667-333 A Armiger-Gibson Island MD 8697 BALTIMORE-WASHINGTON TELEPHONE (BWT) 238      
667-367 A Westminster MD 8697 BALTIMORE-WASHINGTON TELEPHONE (BWT) 238      

Last updated: Thu, 01 Jan 2026 03:59:49 UTC

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