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.

McCook, TX

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
956-557 A HRLNTXHGXFX  508J CENTURYLINK COMMUNICATIONS, LLC 568      
956-557 5   145J TERRA NOVA TELECOM INC. 568   2025-08-15   
956-557 7 HRLNTXHGXFX  508J CENTURYLINK COMMUNICATIONS, LLC 568   2016-07-09   
956-842 A HRGLTXXARS0  2159 VALLEY TEL. COOP., INC. 568      

Last updated: Sun, 07 Dec 2025 22:02:11 UTC

Sponsored by: LES.NET

Like this site? We accept donations via PayPal.