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: 657 [Rate centres in NPA 657] [Dial plan for NPA 657]

NXX: 478

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
657-478 A Brea CA ANHMCACLCM6  6010 NEW CINGULAR WIRELESS PCS, LLC 730      
657-478 0 Brea CA   649C ONVOY, LLC - CA 730   2019-03-03   
657-478 1 Brea CA   649C ONVOY, LLC - CA 730   2019-03-03   
657-478 2 Brea CA   649C ONVOY, LLC - CA 730   2023-05-07   
657-478 3 Brea CA   649C ONVOY, LLC - CA 730   2021-07-22   
657-478 4 Brea CA   707H INTEGRATED PATH COMMUNICATIONS, LLC - CA 730   2018-05-08   
657-478 5 Brea CA   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2019-11-23   
657-478 6 Brea CA   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2019-01-13   
657-478 7 Brea CA   073H TELNYX LLC 730   2018-07-09   
657-478 8 Brea CA   6529 T-MOBILE USA, INC. 730   2017-11-24   
657-478 9 Brea CA   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2017-08-10   

Last updated: Thu, 01 Jan 2026 03:59:49 UTC

Sponsored by: Execulink Telecom

Like this site? We accept donations via PayPal.