Local Calling Guide

Area code/prefix search

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Chicago Zone 01-Monroe, IL

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NPA-NXX BLOCK Switch OCN LATA LIR Eff date Disc date
312-226 A CHCGILMODS1  9329 ILLINOIS BELL TEL CO 358      
312-243 A CHCGILMODS1  9329 ILLINOIS BELL TEL CO 358      
312-260 A BNSVILDGDS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-260 0   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-260 1   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-260 2   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-260 3   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-260 4   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-260 5   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-260 6   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-260 7   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358   2005-12-12   
312-260 8   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-260 9   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-279 A BNSVILDGDS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-355 A CHCGILMODS1  9329 ILLINOIS BELL TEL CO 358      
312-361 A CHCGILMODS1  9329 ILLINOIS BELL TEL CO 358      
312-361 0   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358   2006-12-09   
312-361 1   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358   2010-07-14   
312-361 2   9329 ILLINOIS BELL TEL CO 358      
312-361 3   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358   2010-07-14   
312-361 4   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 358   2011-06-23   
312-361 5   224C ONVOY, LLC 358   2010-10-27   
312-361 6   9329 ILLINOIS BELL TEL CO 358      
312-361 7   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 358   2011-06-23   
312-361 8   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358   2006-12-09   
312-361 9   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358   2010-10-27   
312-363 A CHCGILACGT0  8702 RCN TELECOM SERVICES OF ILLINIOS, INC. - IL 358      
312-363 0   8702 RCN TELECOM SERVICES OF ILLINIOS, INC. - IL 358      
312-363 1   8702 RCN TELECOM SERVICES OF ILLINIOS, INC. - IL 358      
312-363 2   8702 RCN TELECOM SERVICES OF ILLINIOS, INC. - IL 358      
312-363 3   8702 RCN TELECOM SERVICES OF ILLINIOS, INC. - IL 358      
312-363 4   8702 RCN TELECOM SERVICES OF ILLINIOS, INC. - IL 358      
312-363 5   8702 RCN TELECOM SERVICES OF ILLINIOS, INC. - IL 358      
312-363 6   460K FIRST COMMUNICATIONS, LLC 358   2004-06-06   
312-363 7   6529 T-MOBILE USA, INC. 358   2004-07-15   
312-363 8   6529 T-MOBILE USA, INC. 358   2004-07-15   
312-363 9   6529 T-MOBILE USA, INC. 358   2004-07-15   
312-413 A CHCGILMODS1  9329 ILLINOIS BELL TEL CO 358      
312-421 A CHCGILMODS0  9329 ILLINOIS BELL TEL CO 358      
312-432 A CHCGILMODS1  9329 ILLINOIS BELL TEL CO 358      
312-433 A CHCGILMODS0  9329 ILLINOIS BELL TEL CO 358      
312-433 0   9329 ILLINOIS BELL TEL CO 358      
312-433 1   9329 ILLINOIS BELL TEL CO 358      
312-433 2   9329 ILLINOIS BELL TEL CO 358      
312-433 3   9329 ILLINOIS BELL TEL CO 358      
312-433 4   9329 ILLINOIS BELL TEL CO 358      
312-433 5   9329 ILLINOIS BELL TEL CO 358      
312-433 6   9329 ILLINOIS BELL TEL CO 358      
312-433 7   9329 ILLINOIS BELL TEL CO 358      
312-433 8   9329 ILLINOIS BELL TEL CO 358      
312-433 9   6333 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 358   2011-01-14   
312-455 A CHCGILMODS1  9329 ILLINOIS BELL TEL CO 358      
312-470 A BNSVILDGDS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-470 0   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-470 1   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-470 2   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-470 3   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-470 4   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-470 5   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-470 6   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358   2010-11-20   
312-470 7   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-470 8   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-470 9   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-491 A CHCGILMODS0  9329 ILLINOIS BELL TEL CO 358      
312-492 A CHCGILMODS1  9329 ILLINOIS BELL TEL CO 358      
312-492 0   9329 ILLINOIS BELL TEL CO 358      
312-492 1   9329 ILLINOIS BELL TEL CO 358      
312-492 2   9329 ILLINOIS BELL TEL CO 358      
312-492 3   9329 ILLINOIS BELL TEL CO 358      
312-492 4   6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358   2006-10-25   
312-492 5   9329 ILLINOIS BELL TEL CO 358      
312-492 6   9329 ILLINOIS BELL TEL CO 358      
312-492 7   9329 ILLINOIS BELL TEL CO 358      
312-492 8   9329 ILLINOIS BELL TEL CO 358      
312-492 9   9329 ILLINOIS BELL TEL CO 358      
312-563 A CHCGILMODS1  9329 ILLINOIS BELL TEL CO 358      
312-569 A CHCGILMODS1  9329 ILLINOIS BELL TEL CO 358      
312-569 0   984E BANDWIDTH.COM CLEC, LLC - IL 358   2010-03-04   
312-569 1   7136 TELEPORT COMMUNICATIONS AMERICA, LLC - IL 358   2002-06-24   
312-569 2   5562 METROPCS, INC. 358   2017-02-05   
312-569 3   224C ONVOY, LLC 358   2002-06-24   
312-569 4   9329 ILLINOIS BELL TEL CO 358   2002-06-24   
312-569 5   9329 ILLINOIS BELL TEL CO 358      
312-569 6   9329 ILLINOIS BELL TEL CO 358      
312-569 7   9329 ILLINOIS BELL TEL CO 358      
312-569 8   9329 ILLINOIS BELL TEL CO 358      
312-569 9   984E BANDWIDTH.COM CLEC, LLC - IL 358   2010-03-04   
312-572 A CHCGILMODS0  9329 ILLINOIS BELL TEL CO 358      
312-572 0   5562 METROPCS, INC. 358   2017-02-05   
312-572 1   9329 ILLINOIS BELL TEL CO 358      
312-572 2   9329 ILLINOIS BELL TEL CO 358      
312-572 3   9329 ILLINOIS BELL TEL CO 358      
312-572 4   9329 ILLINOIS BELL TEL CO 358      
312-572 5   9329 ILLINOIS BELL TEL CO 358      
312-572 6   829J PAETEC ITEL, LLC 358   2009-09-29   
312-572 7   829J PAETEC ITEL, LLC 358   2007-12-14   
312-572 8   829J PAETEC ITEL, LLC 358   2009-09-29   
312-572 9   984E BANDWIDTH.COM CLEC, LLC - IL 358   2010-03-04   
312-601 A BNSVILDGDS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-633 A CHCGILMODS0  9329 ILLINOIS BELL TEL CO 358      

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

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