Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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Preemption, IL

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
309-534 A PRMPILXDRS0  1183 CITIZENS TELECOM CO ILLINOIS-FRONTIER CITIZENS -IL 634      
309-600 A RCISILRIWMD  846F MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL 634      
309-600 0   495J STRATUS NETWORKS 634   2020-10-14   
309-600 1   846F MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL 634   2010-04-15   
309-600 3   224C ONVOY, LLC 634   2021-04-05   
309-600 6   224C ONVOY, LLC 634   2020-04-29   
309-600 7   508J CENTURYLINK COMMUNICATIONS, LLC 634   2016-10-13   

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

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