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.

Washington Zone 14, MD

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NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date

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Last updated: Sat, 21 Mar 2026 23:53:39 UTC

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