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: 770

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
423-770 A Church Hill TN JHCYTNXCXPX  525E ONVOY, LLC - TN 956      
423-770 0 Church Hill TN JHCYTNXCXPX  525E ONVOY, LLC - TN 956   2021-03-15   
423-770 1 Church Hill TN JHCYTNXCXPX  525E ONVOY, LLC - TN 956   2021-03-15   
423-770 2 Church Hill TN JHCYTNXCXPY  624H ONVOY SPECTRUM, LLC 956   2023-04-27   
423-770 3 Church Hill TN JHCYTNXCXPX  525E ONVOY, LLC - TN 956   2023-09-09   
423-770 4 Church Hill TN JHCYTNXC9MD  4806 LEVEL 3 COMMUNICATIONS, LLC - TN 956   2021-05-27   
423-770 7 Church Hill TN JHCYTNXCXPX  525E ONVOY, LLC - TN 956   2018-09-21   
423-770 8 Church Hill TN JHCYTNXCXPX  525E ONVOY, LLC - TN 956   2018-09-21   
423-770 9 Church Hill TN JHCYTNXCXAY  073H TELNYX LLC 956   2022-06-22   

Last updated: Thu, 16 Oct 2025 03:04:18 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.