Local Calling Guide

Area code/prefix search

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

NXX: 821

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
231-821 A Holton MI HLTNMIXGRS0  0695 FRONTIER NORTH, INC. - MI 348      
231-821 0 Holton MI   0695 FRONTIER NORTH, INC. - MI 348      
231-821 1 Holton MI   0695 FRONTIER NORTH, INC. - MI 348      
231-821 2 Holton MI   0695 FRONTIER NORTH, INC. - MI 348      
231-821 3 Holton MI   6120 LEVEL 3 COMMUNICATIONS, LLC - MI 348   2004-11-12   
231-821 4 Holton MI   3535 ACD TELECOM, INC. - MI 348   2005-02-11   
231-821 5 Holton MI   6120 LEVEL 3 COMMUNICATIONS, LLC - MI 348   2006-01-14   
231-821 6 Holton MI   543C ONVOY, LLCV - MI 348   2013-03-18   
231-821 7 Holton MI   318J COMCAST IP PHONE, LLC 348   2007-06-08   
231-821 8 Holton MI   508J CENTURYLINK COMMUNICATIONS, LLC 348   2015-09-15   
231-821 9 Holton MI   0695 FRONTIER NORTH, INC. - MI 348      

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

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