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: CRCYAZNMRS1

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
623-388 A Phoenix AZ 9636 QWEST CORPORATION 666      
623-388 0 Phoenix AZ 9636 QWEST CORPORATION 666      
623-388 2 Phoenix AZ 9636 QWEST CORPORATION 666      
623-388 9 Phoenix AZ 9636 QWEST CORPORATION 666      

Last updated: Tue, 31 Mar 2026 13:56:49 UTC

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