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: WASIDCRG7MD

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
202-971 A Washington Zone 1 DC 508J CENTURYLINK COMMUNICATIONS, LLC 236      
240-901 A La Plata MD 508J CENTURYLINK COMMUNICATIONS, LLC 236      
410-834 A Waterloo (Washington DC LATA) MD 508J CENTURYLINK COMMUNICATIONS, LLC 236      

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

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