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.

NPA: 301 [Rate centres in NPA 301] [Dial plan for NPA 301]

NXX: 981

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
301-981 A Washington Zone 5 MD LARLMDCC5MD  7591 LEVEL 3 TELECOM OF MARYLAND, LLC - MD 236      

Last updated: Thu, 16 Oct 2025 03:04:18 UTC

Sponsored by: LES.NET

Like this site? We accept donations via PayPal.