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: 956 [Rate centres in NPA 956] [Dial plan for NPA 956]

NXX: 577

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
956-577 A Harlingen TX HRLNTXHGDS0  9533 SOUTHWESTERN BELL 568      
956-577 0 Harlingen TX HRLNTXHGDS0  9533 SOUTHWESTERN BELL 568      
956-577 1 Harlingen TX HRLNTXHGX7X  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 568      
956-577 2 Harlingen TX HRLNTXHGX7X  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 568      
956-577 3 Harlingen TX HRLNTXHGX7X  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 568      
956-577 4 Harlingen TX HRLNTXHGX7X  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 568      
956-577 5 Harlingen TX HRLNTXHGX7X  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 568      
956-577 6 Harlingen TX HRLNTXHGX7X  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 568      
956-577 7 Harlingen TX HRLNTXHGX7X  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 568      
956-577 8 Harlingen TX   145J TERRA NOVA TELECOM INC. 568      
956-577 9 Harlingen TX HRLNTXDU7MD  145J TERRA NOVA TELECOM INC. 568      

Last updated: Wed, 20 Nov 2024 21:20:06 UTC

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.