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: 628 [Rate centres in NPA 628] [Dial plan for NPA 628]

NXX: 677

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
628-677 A Mill Valley CA SNJUCACL7MD  965H FRACTEL, LLC 722      
628-677 0 Mill Valley CA   5562 METROPCS, INC. 722   2022-05-06   
628-677 1 Mill Valley CA   649C ONVOY, LLC - CA 722   2023-08-11   
628-677 2 Mill Valley CA   649C ONVOY, LLC - CA 722   2023-08-11   
628-677 3 Mill Valley CA   649C ONVOY, LLC - CA 722   2021-10-03   
628-677 4 Mill Valley CA   649C ONVOY, LLC - CA 722   2021-10-03   
628-677 5 Mill Valley CA   649C ONVOY, LLC - CA 722   2021-10-03   
628-677 6 Mill Valley CA   649C ONVOY, LLC - CA 722   2021-10-03   
628-677 7 Mill Valley CA   965H FRACTEL, LLC 722   2021-09-13   
628-677 8 Mill Valley CA   649C ONVOY, LLC - CA 722   2023-08-11   
628-677 9 Mill Valley CA   939H COMMIO, LLC 722   2022-11-10   

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

Sponsored by: VoIP.ms

Like this site? We accept donations via PayPal.