Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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Chicago Zone 01-Lakeshore, IL

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NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
312-650 9   984E BANDWIDTH.COM CLEC, LLC - IL 358   2010-03-04   
312-653 A CHCGILLRDS0  9329 ILLINOIS BELL TEL CO 358      
312-729 A CHCGILLRDS0  9329 ILLINOIS BELL TEL CO 358      
312-819 A CHCGILLRDS0  9329 ILLINOIS BELL TEL CO 358      
312-856 A CHCGILLRDS0  9329 ILLINOIS BELL TEL CO 358      
312-856 0   9329 ILLINOIS BELL TEL CO 358      
312-856 1   9329 ILLINOIS BELL TEL CO 358      
312-856 2   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 358   2015-01-03   
312-856 3   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 358   2015-01-03   
312-856 4   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 358   2015-01-03   
312-856 5   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 358   2015-01-03   
312-856 6   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 358   2015-01-03   
312-856 7   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 358   2015-01-03   
312-856 8   9329 ILLINOIS BELL TEL CO 358      
312-856 9   9329 ILLINOIS BELL TEL CO 358      
312-861 A CHCGILLRDS0  9329 ILLINOIS BELL TEL CO 358      
312-938 A CHCGILLRDS0  9329 ILLINOIS BELL TEL CO 358      
312-946 A CHCGILLRDS0  9329 ILLINOIS BELL TEL CO 358      

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

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