Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 312 [Rate centres in NPA 312] [Dial plan for NPA 312]

NXX: 256

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
312-256 A Chicago Zone 01-Calumet IL   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-256 0 Chicago Zone 01-Calumet IL   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-256 1 Chicago Zone 01-Calumet IL RVDLILBDAMD  6333 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 358   2010-08-16   
312-256 2 Chicago Zone 01-Calumet IL   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      
312-256 3 Chicago Zone 01-Calumet IL RVDLILBDAMD  6333 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL 358   2010-08-16   
312-256 4 Chicago Zone 01-Calumet IL BURGILAHGT3  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 358   2010-03-01   
312-256 5 Chicago Zone 01-Calumet IL BURGILAHGT3  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 358   2010-03-01   
312-256 6 Chicago Zone 01-Calumet IL BURGILAHGT3  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 358   2010-03-01   
312-256 7 Chicago Zone 01-Calumet IL BURGILAHGT3  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 358   2010-03-01   
312-256 8 Chicago Zone 01-Calumet IL CHCGILAEDS3  5917 FIRST COMMUNICATIONS, LLC 358   2009-01-31   
312-256 9 Chicago Zone 01-Calumet IL   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358      

Last updated: Fri, 13 May 2022 22:16:13 UTC

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