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: 478

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
346-478 A Spring TX HSTNTXGI0MD  004F BANDWIDTH.COM CLEC, LLC - TX 560      
346-478 0 Spring TX   004F BANDWIDTH.COM CLEC, LLC - TX 560   2021-09-02   
346-478 1 Spring TX   004F BANDWIDTH.COM CLEC, LLC - TX 560   2021-09-02   
346-478 2 Spring TX   939H COMMIO, LLC 560   2021-09-03   
346-478 3 Spring TX   939H COMMIO, LLC 560   2021-09-03   
346-478 4 Spring TX   939H COMMIO, LLC 560   2021-09-03   
346-478 5 Spring TX   903C ONVOY, LLC - TX 560   2021-09-03   
346-478 6 Spring TX   903C ONVOY, LLC - TX 560   2021-09-03   
346-478 7 Spring TX   903C ONVOY, LLC - TX 560   2021-09-03   
346-478 8 Spring TX   903C ONVOY, LLC - TX 560   2021-09-03   
346-478 9 Spring TX   939H COMMIO, LLC 560   2021-09-03   

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.