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: 320

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
628-320 A San Francisco: Montrose-Evergreen DA CA   624H ONVOY SPECTRUM, LLC 722   2025-03-21   
628-320 0 San Francisco: Montrose-Evergreen DA CA   624H ONVOY SPECTRUM, LLC 722   2025-03-21   
628-320 8 San Francisco: Montrose-Evergreen DA CA   6006 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 722   2025-11-12   
628-320 9 San Francisco: Montrose-Evergreen DA CA   6006 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CA 722   2025-11-12   

Last updated: Sat, 02 May 2026 12:20:53 UTC

Sponsored by: VoIP Much Phone Company

Like this site? We accept donations via PayPal.