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: 251

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
231-251 A Lake Leelanau MI BRSPMI09DS0  933G PEERLESS NETWORK OF MICHIGAN, LLC - MI 348      
231-251 0 Lake Leelanau MI BRSPMI09DS0  933G PEERLESS NETWORK OF MICHIGAN, LLC - MI 348   2019-10-25   
231-251 1 Lake Leelanau MI BRSPMI09DS0  933G PEERLESS NETWORK OF MICHIGAN, LLC - MI 348   2016-01-23   
231-251 2 Lake Leelanau MI GDRPMIBL04Z  543C ONVOY, LLCV - MI 348   2018-09-13   
231-251 3 Lake Leelanau MI GDRPMIBL36Z  624H ONVOY SPECTRUM, LLC 348   2021-06-19   
231-251 4 Lake Leelanau MI GDRPMIBL04Z  543C ONVOY, LLCV - MI 348   2021-07-11   
231-251 5 Lake Leelanau MI GDRPMIBL04Z  543C ONVOY, LLCV - MI 348   2021-04-25   
231-251 7 Lake Leelanau MI GDRPMIBL04Z  543C ONVOY, LLCV - MI 348   2016-03-24   
231-251 8 Lake Leelanau MI GDRPMIBL04Z  543C ONVOY, LLCV - MI 348   2016-03-24   
231-251 9 Lake Leelanau MI BRSPMI09DS0  933G PEERLESS NETWORK OF MICHIGAN, LLC - MI 348   2018-09-29   

Last updated: Sun, 26 Jan 2025 15:59:20 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.