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.

Switch: HSTNTXMOIMD

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
281-434 A Houston TX 9748 AMERICAN MESSAGING SERVICES, LLC 560      
281-567 A Houston TX 9748 AMERICAN MESSAGING SERVICES, LLC 560      
713-317 A Houston TX 9748 AMERICAN MESSAGING SERVICES, LLC 560      
713-727 A Houston TX 9748 AMERICAN MESSAGING SERVICES, LLC 560      
713-908 A Houston TX 9748 AMERICAN MESSAGING SERVICES, LLC 560      

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

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