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: 231 [Rate centres in NPA 231] [Dial plan for NPA 231]

NXX: 974

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
231-974 A Grant MI GDRPMIBLX8Z  2550 123.NET, INC. 348      
231-974 0 Grant MI GDRPMIBLX8Z  2550 123.NET, INC. 348      
231-974 1 Grant MI   515J IP HORIZON LLC 348   2021-12-31   
231-974 2 Grant MI GDRPMIBL00Z  991E BANDWIDTH.COM CLEC, LLC - MI 348   2022-09-23   
231-974 3 Grant MI GDRPMIBL04Z  543C ONVOY, LLCV - MI 348   2021-03-06   
231-974 4 Grant MI GDRPMIBL04Z  543C ONVOY, LLCV - MI 348   2021-03-06   
231-974 5 Grant MI BRSPMI096MD  145J TERRA NOVA TELECOM INC. 348   2023-06-24   
231-974 6 Grant MI GDRPMIBL36Z  624H ONVOY SPECTRUM, LLC 348   2021-06-19   
231-974 7 Grant MI GDRPMIBL41Z  506J TWILIO INTERNATIONAL, INC. 348   2021-07-26   

Last updated: Fri, 22 Mar 2024 03:02:44 UTC

Sponsored by: VoIP.ms

Like this site? We accept donations via PayPal.