Local Calling Guide

Area code/prefix search

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Chicago Zone 01-Calumet, IL

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NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
312-628 1   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-628 2   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-628 3   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-628 4   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-628 5   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-628 6   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-628 7   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-628 8   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-628 9   6333 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 358   2025-12-04   
312-631 A CHCGILDT8MD  508J CENTURYLINK COMMUNICATIONS, LLC 358      
312-631 0   224C ONVOY, LLC 358   2013-05-24   
312-631 1   224C ONVOY, LLC 358   2013-05-24   
312-631 2   7136 TELEPORT COMMUNICATIONS AMERICA, LLC - IL 358   2013-07-05   
312-631 3   516C AT&T CORP. 358   2013-07-03   
312-631 4   5562 METROPCS, INC. 358   2013-05-01   
312-631 5   5562 METROPCS, INC. 358   2013-05-01   
312-631 6   5562 METROPCS, INC. 358   2013-05-01   
312-631 7   508J CENTURYLINK COMMUNICATIONS, LLC 358   2013-05-31   
312-631 8   5562 METROPCS, INC. 358   2013-05-01   
312-631 9   5562 METROPCS, INC. 358   2013-05-01   
312-635 A   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-635 0   6333 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 358   2025-12-04   
312-635 1   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-635 2   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-635 3   460K FIRST COMMUNICATIONS, LLC 358   2014-06-15   
312-635 4   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-635 5   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-635 6   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-635 7   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-635 8   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-635 9   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-637 A CHCGILGMDS7  6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-637 0   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 358   2011-08-07   
312-637 1   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-637 2   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-637 3   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-637 4   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-637 5   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-637 6   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-637 7   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-637 8   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-637 9   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-638 A CHCGILGMDS7  6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-638 0   073H TELNYX LLC 358   2022-08-25   
312-638 1   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-638 2   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-638 3   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-638 4   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      
312-638 5   138G LEVEL 3 TELECOM OF ILLINOIS, LLC - IL 358   2015-04-24   
312-638 6   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358      

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

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