Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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White, SD

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
605-304 A CLLKSDXA0MD  920F MCC TELEPHONY OF THE MID-WEST, LLC - SD 640      
605-304 1   920F MCC TELEPHONY OF THE MID-WEST, LLC - SD 640   2010-09-26   
605-629 A CLLKSDXADS0  1651 INTERSTATE TELECOM COOP, INC. - SD 640      

Last updated: Tue, 13 Jan 2026 21:50:02 UTC

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