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: 558

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
423-558 A Chattanooga TN CHTGTNNSXKY  525E ONVOY, LLC - TN 472      
423-558 0 Chattanooga TN CHTGTNNSXKY  525E ONVOY, LLC - TN 472   2007-03-17   
423-558 1 Chattanooga TN CHTGTNGZ4MD  6214 NEW CINGULAR WIRELESS PCS, LLC - GA 472   2020-03-07   
423-558 2 Chattanooga TN CHTGTNNSXKY  525E ONVOY, LLC - TN 472   2018-06-11   
423-558 3 Chattanooga TN CHTGTNNSXKY  525E ONVOY, LLC - TN 472   2019-05-24   
423-558 4 Chattanooga TN CHTGTNGZ4MD  6214 NEW CINGULAR WIRELESS PCS, LLC - GA 472   2020-03-07   
423-558 5 Chattanooga TN CHTGTNNSXMZ  624H ONVOY SPECTRUM, LLC 472   2021-11-12   
423-558 6 Chattanooga TN CHTGTNGZ4MD  6214 NEW CINGULAR WIRELESS PCS, LLC - GA 472   2020-03-07   
423-558 7 Chattanooga TN CHTGTNGZ4MD  6214 NEW CINGULAR WIRELESS PCS, LLC - GA 472   2020-03-07   
423-558 8 Chattanooga TN CHTGTNNSXMZ  624H ONVOY SPECTRUM, LLC 472   2021-11-12   
423-558 9 Chattanooga TN CHTGTNGZ4MD  6214 NEW CINGULAR WIRELESS PCS, LLC - GA 472   2020-03-07   

Last updated: Sat, 05 Apr 2025 03:03:23 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.