Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 231 [Rate centres in NPA 231] [Dial plan for NPA 231]

NXX: 438

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
231-438 A Harbor Springs MI GDRPMIBL04Z  543C ONVOY, LLCV - MI 348      
231-438 2 Harbor Springs MI GDRPMIBL04Z  543C ONVOY, LLCV - MI 348   2023-09-16   
231-438 4 Harbor Springs MI   883K AHOI LLC 348   2026-05-23   
231-438 7 Harbor Springs MI   114J EXIANT COMMUNICATIONS LLC 348   2026-05-23   

Last updated: Sat, 02 May 2026 12:20:53 UTC

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