Local Calling Guide

Area code/prefix search

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

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NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
312-799 7   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358   2000-08-29   
312-799 8   9329 ILLINOIS BELL TEL CO 358   2000-11-18   
312-799 9   6529 T-MOBILE USA, INC. 358   2005-01-04   
312-821 A EGVGILIFDS1  7196 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - IL 358      
312-821 0   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-821 1   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-821 2   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-821 3   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-821 4   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-821 5   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-821 6   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-821 7   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-821 8   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-821 9   7196 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - IL 358      
312-867 A CHCGILSUDS0  9329 ILLINOIS BELL TEL CO 358      
312-908 A CHCGILSUDS2  9329 ILLINOIS BELL TEL CO 358      
312-915 A CHCGILSUDS2  9329 ILLINOIS BELL TEL CO 358      
312-926 A CHCGILSUDS2  9329 ILLINOIS BELL TEL CO 358      
312-932 A CHCGILSUDS0  9329 ILLINOIS BELL TEL CO 358      
312-932 0   9329 ILLINOIS BELL TEL CO 358      
312-932 1   9329 ILLINOIS BELL TEL CO 358      
312-932 2   9329 ILLINOIS BELL TEL CO 358      
312-932 3   9329 ILLINOIS BELL TEL CO 358      
312-932 4   9329 ILLINOIS BELL TEL CO 358      
312-932 5   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358   2001-12-06   
312-932 6   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358   2000-07-07   
312-932 7   624H ONVOY SPECTRUM, LLC 358   2022-04-09   
312-932 8   9329 ILLINOIS BELL TEL CO 358      
312-932 9   9329 ILLINOIS BELL TEL CO 358      
312-943 A CHCGILSUDS2  9329 ILLINOIS BELL TEL CO 358      
312-944 A CHCGILSUDS2  9329 ILLINOIS BELL TEL CO 358      
312-951 A CHCGILSUDS2  9329 ILLINOIS BELL TEL CO 358      
312-951 0   9329 ILLINOIS BELL TEL CO 358      
312-951 1   9329 ILLINOIS BELL TEL CO 358      
312-951 2   9329 ILLINOIS BELL TEL CO 358      
312-951 3   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 358   2015-01-03   
312-951 4   9329 ILLINOIS BELL TEL CO 358      
312-951 5   9329 ILLINOIS BELL TEL CO 358      
312-951 6   9329 ILLINOIS BELL TEL CO 358      
312-951 7   9329 ILLINOIS BELL TEL CO 358      
312-951 8   9329 ILLINOIS BELL TEL CO 358      
312-951 9   9329 ILLINOIS BELL TEL CO 358      
312-979 A CHCGILSUDS0  9329 ILLINOIS BELL TEL CO 358      
312-988 A CHCGILSUDS2  9329 ILLINOIS BELL TEL CO 358      
312-988 0   318J COMCAST IP PHONE, LLC 358   2012-12-31   
312-988 1   9329 ILLINOIS BELL TEL CO 358      
312-988 2   9329 ILLINOIS BELL TEL CO 358      
312-988 3   9329 ILLINOIS BELL TEL CO 358      
312-988 4   9329 ILLINOIS BELL TEL CO 358      
312-988 5   9329 ILLINOIS BELL TEL CO 358      
312-988 6   9329 ILLINOIS BELL TEL CO 358      
312-988 7   9329 ILLINOIS BELL TEL CO 358      
312-988 8   9329 ILLINOIS BELL TEL CO 358      
312-988 9   9329 ILLINOIS BELL TEL CO 358      

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Last updated: Thu, 01 Jan 2026 03:59:49 UTC

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