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.

Switch: SNFCCAMM8MD

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
415-400 A San Francisco: Central DA CA 973E RACE TELECOMMUNICATIONS, INC. - CA 722      
415-400 1 San Francisco: Central DA CA 973E RACE TELECOMMUNICATIONS, INC. - CA 722   2009-03-16   
628-257 A Mill Valley CA 973E RACE TELECOMMUNICATIONS, INC. - CA 722      
628-257 0 Mill Valley CA 973E RACE TELECOMMUNICATIONS, INC. - CA 722   2016-12-25   

Last updated: Wed, 04 Mar 2026 03:00:52 UTC

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