Local Calling Guide

Area code/prefix search

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

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
309-658 A HLDLILXDRS0  1183 CITIZENS TELECOM CO ILLINOIS-FRONTIER CITIZENS -IL 634      
309-771 A RCISILRIWMD  846F MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL 634      
309-771 1 RCISILRIWMD  846F MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL 634   2010-04-15   
309-771 3 DVNPIADTXQX  224C ONVOY, LLC 634   2021-04-05   
309-771 5 DVNPIADTXQX  224C ONVOY, LLC 634   2020-04-29   
309-771 7 RCISILRIX0X  508J CENTURYLINK COMMUNICATIONS, LLC 634   2016-10-12   
309-771 8 HMPNILXDAMD  495J STRATUS NETWORKS 634   2020-12-17   

Last updated: Sun, 07 Dec 2025 22:02:11 UTC

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