Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
  • Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information.
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Chicago Zone 08-Prospect, IL

NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
773-434 A CHCGILPRDS0  9329 ILLINOIS BELL TEL CO 358      
773-436 A CHCGILPRDS0  9329 ILLINOIS BELL TEL CO 358      
773-471 A CHCGILPRDS0  9329 ILLINOIS BELL TEL CO 358      
773-476 A CHCGILPRDS0  9329 ILLINOIS BELL TEL CO 358      
773-737 A CHCGILPRDS0  9329 ILLINOIS BELL TEL CO 358      
773-776 A CHCGILPRDS0  9329 ILLINOIS BELL TEL CO 358      
773-778 A CHCGILPRDS0  9329 ILLINOIS BELL TEL CO 358      
773-863 A CHCGILPRDS0  9329 ILLINOIS BELL TEL CO 358      
773-863 0   9329 ILLINOIS BELL TEL CO 358      
773-863 1   9329 ILLINOIS BELL TEL CO 358      
773-863 2   6529 T-MOBILE USA, INC. 358   2012-10-05   
773-863 3   224C ONVOY, LLC 358   2013-07-31   
773-863 4   9329 ILLINOIS BELL TEL CO 358      
773-863 5   9329 ILLINOIS BELL TEL CO 358      
773-863 6   9329 ILLINOIS BELL TEL CO 358      
773-863 7   9329 ILLINOIS BELL TEL CO 358      
773-863 8   9329 ILLINOIS BELL TEL CO 358      
773-863 9   9329 ILLINOIS BELL TEL CO 358      
773-918 A CHCGILPRDS0  9329 ILLINOIS BELL TEL CO 358      
773-918 0   9329 ILLINOIS BELL TEL CO 358      
773-918 1   9329 ILLINOIS BELL TEL CO 358      
773-918 2   224C ONVOY, LLC 358   2016-03-07   
773-918 3   9329 ILLINOIS BELL TEL CO 358      
773-918 4   9329 ILLINOIS BELL TEL CO 358      
773-918 5   6529 T-MOBILE USA, INC. 358   2007-03-19   
773-918 6   9329 ILLINOIS BELL TEL CO 358      
773-918 7   9329 ILLINOIS BELL TEL CO 358      
773-918 8   9329 ILLINOIS BELL TEL CO 358      
773-918 9   6529 T-MOBILE USA, INC. 358   2007-03-19   
773-925 A CHCGILPRDS0  9329 ILLINOIS BELL TEL CO 358      

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

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