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: SNANTXCA40Z

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
210-203 A San Antonio TX 9748 AMERICAN MESSAGING SERVICES, LLC 566      
210-205 A San Antonio TX 9748 AMERICAN MESSAGING SERVICES, LLC 566      
210-217 A San Antonio TX 9748 AMERICAN MESSAGING SERVICES, LLC 566      
210-266 A San Antonio TX 9748 AMERICAN MESSAGING SERVICES, LLC 566      

Last updated: Thu, 16 Oct 2025 03:04:18 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.