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: 540

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
423-540 A Newport TN KNVLTNMA49Z  525E ONVOY, LLC - TN 474      
423-540 0 Newport TN   525E ONVOY, LLC - TN 474   2018-04-18   
423-540 1 Newport TN   525E ONVOY, LLC - TN 474   2018-04-19   
423-540 2 Newport TN   6214 NEW CINGULAR WIRELESS PCS, LLC - GA 474   2023-04-08   
423-540 3 Newport TN   6214 NEW CINGULAR WIRELESS PCS, LLC - GA 474   2023-04-08   
423-540 4 Newport TN   525E ONVOY, LLC - TN 474   2021-03-04   
423-540 5 Newport TN   525E ONVOY, LLC - TN 474   2020-12-21   
423-540 6 Newport TN   6673 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TN 474   2020-06-16   
423-540 8 Newport TN   525E ONVOY, LLC - TN 474   2022-05-21   
423-540 9 Newport TN   525E ONVOY, LLC - TN 474   2021-07-30   

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

Sponsored by: Execulink Telecom

Like this site? We accept donations via PayPal.