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: 423 [Rate centres in NPA 423] [Dial plan for NPA 423]

NXX: 289

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
423-289 A Morristown TN KNVLTNMA96Z  7476 POWERTEL NASHVILLE LICENSES, INC. 474      
423-289 0 Morristown TN   829J PAETEC ITEL, LLC 474   2004-03-27   
423-289 1 Morristown TN   829J PAETEC ITEL, LLC 474   2010-04-23   
423-289 2 Morristown TN   7476 POWERTEL NASHVILLE LICENSES, INC. 474   2011-03-13   
423-289 3 Morristown TN   525E ONVOY, LLC - TN 474   2008-06-10   
423-289 4 Morristown TN   525E ONVOY, LLC - TN 474   2008-06-16   
423-289 5 Morristown TN   145J TERRA NOVA TELECOM INC. 474   2024-12-29   
423-289 8 Morristown TN   145J TERRA NOVA TELECOM INC. 474   2025-10-04   

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

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.