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: JHCYTNXCXWY

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
423-906 A Johnson City TN 475J CALLWORKS CORPORATION 956      
423-906 1 Johnson City TN 475J CALLWORKS CORPORATION 956   2023-12-15   

Last updated: Sat, 15 Nov 2025 03:38:44 UTC

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