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: 538

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
231-538 A Fremont MI GDRPMIBLX8Z  2550 123.NET, INC. 348      
231-538 0 Fremont MI GDRPMIBLX8Z  2550 123.NET, INC. 348      
231-538 1 Fremont MI BRSPMI09DS0  933G PEERLESS NETWORK OF MICHIGAN, LLC - MI 348   2015-12-22   
231-538 2 Fremont MI GDRPMIBL04Z  543C ONVOY, LLCV - MI 348   2016-02-22   
231-538 3 Fremont MI GDRPMIBL04Z  543C ONVOY, LLCV - MI 348   2016-02-22   
231-538 4 Fremont MI GDRPMIQLX5Y  6120 LEVEL 3 COMMUNICATIONS, LLC - MI 348   2012-02-23   
231-538 5 Fremont MI GDRPMIBL06Z  770E TELEPORT COMMUNICATIONS AMERICA, LLC - MI 348   2013-08-06   
231-538 6 Fremont MI GDRPMIBL04Z  543C ONVOY, LLCV - MI 348   2016-04-28   
231-538 7 Fremont MI GDRPMIBL04Z  543C ONVOY, LLCV - MI 348   2016-04-28   
231-538 8 Fremont MI GDRPMIBL00Z  991E BANDWIDTH.COM CLEC, LLC - MI 348   2016-08-22   
231-538 9 Fremont MI BRSPMI096MD  145J TERRA NOVA TELECOM INC. 348   2021-01-19   

Last updated: Wed, 12 Jan 2022 16:20:07 UTC

Sponsored by: LES.NET

Like this site? We accept donations via PayPal.