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: BLTMMDCHYMD

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
227-777 A Ashton (Baltimore LATA) MD 530H WIDE VOICE, LLC - MD 238      
227-777 7 Ashton (Baltimore LATA) MD 530H WIDE VOICE, LLC - MD 238   2023-09-30   
227-888 A Washington Zone 15 (Baltimore LATA) MD 530H WIDE VOICE, LLC - MD 238      
227-888 8 Washington Zone 15 (Baltimore LATA) MD 530H WIDE VOICE, LLC - MD 238   2023-11-20   
667-771 A Baltimore MD 530H WIDE VOICE, LLC - MD 238      
667-771 1 Baltimore MD 530H WIDE VOICE, LLC - MD 238   2016-02-04   

Last updated: Mon, 15 Sep 2025 02:24:40 UTC

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