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: 346 [Rate centres in NPA 346] [Dial plan for NPA 346]

NXX: 506

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
346-506 A Houston TX HSTNTXMOX6X  624H ONVOY SPECTRUM, LLC 560      
346-506 0 Houston TX   490J DISH WIRELESS, LLC 560   2024-11-12   
346-506 1 Houston TX   624H ONVOY SPECTRUM, LLC 560   2021-11-19   
346-506 2 Houston TX   624H ONVOY SPECTRUM, LLC 560   2021-11-19   
346-506 3 Houston TX   624H ONVOY SPECTRUM, LLC 560   2021-11-19   
346-506 4 Houston TX   624H ONVOY SPECTRUM, LLC 560   2021-11-19   
346-506 5 Houston TX   624H ONVOY SPECTRUM, LLC 560   2021-11-19   
346-506 6 Houston TX   624H ONVOY SPECTRUM, LLC 560   2021-11-19   
346-506 7 Houston TX   624H ONVOY SPECTRUM, LLC 560   2021-11-19   
346-506 8 Houston TX   624H ONVOY SPECTRUM, LLC 560   2021-11-19   
346-506 9 Houston TX   624H ONVOY SPECTRUM, LLC 560   2021-11-19   

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.