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: 240 [Rate centres in NPA 240] [Dial plan for NPA 240]

NXX: 634

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
240-634 A Ridge MD CHCHMDBEPS0  2593 CORE COMMUNICATIONS, INC.- MD 236   2024-01-16   
240-634 0 Ridge MD   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-08-02   
240-634 1 Ridge MD   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-08-02   
240-634 2 Ridge MD   2593 CORE COMMUNICATIONS, INC.- MD 236   2018-08-02   
240-634 3 Ridge MD   876D ONVOY, LLC - MD 236   2020-10-17   
240-634 4 Ridge MD   2593 CORE COMMUNICATIONS, INC.- MD 236   2019-07-30   
240-634 5 Ridge MD   2593 CORE COMMUNICATIONS, INC.- MD 236   2019-07-30   
240-634 6 Ridge MD   2593 CORE COMMUNICATIONS, INC.- MD 236   2019-03-29   
240-634 7 Ridge MD   2593 CORE COMMUNICATIONS, INC.- MD 236   2019-03-29   
240-634 8 Ridge MD   876D ONVOY, LLC - MD 236   2019-02-19   
240-634 9 Ridge MD   876D ONVOY, LLC - MD 236   2019-02-19   

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.