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: 666

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
301-666 A Washington Zone 14 MD WASHDCTTDS0  7529 TELEPORT COMMUNICATIONS AMERICA, LLC - DC 236      
301-666 0 Washington Zone 14 MD   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-06-16   
301-666 1 Washington Zone 14 MD   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-10-23   
301-666 2 Washington Zone 14 MD VINNVACBDS0  876D ONVOY, LLC - MD 236   2017-12-14   
301-666 3 Washington Zone 14 MD WASHDCTTDS0  7529 TELEPORT COMMUNICATIONS AMERICA, LLC - DC 236      
301-666 4 Washington Zone 14 MD   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-10-23   
301-666 5 Washington Zone 14 MD   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-06-16   
301-666 6 Washington Zone 14 MD   2593 CORE COMMUNICATIONS, INC.- MD 236   2012-08-26   
301-666 7 Washington Zone 14 MD WASIDCRG7MD  508J CENTURYLINK COMMUNICATIONS, LLC 236   2014-04-02   
301-666 8 Washington Zone 14 MD   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-06-16   
301-666 9 Washington Zone 14 MD   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-10-23   

Last updated: Tue, 16 Apr 2024 01:38:01 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.