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: 554

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
312-554 A Chicago Zone 01-Wabash IL CHCGILWBDS0  9329 ILLINOIS BELL TEL CO 358      
312-554 1 Chicago Zone 01-Wabash IL CHCGILWBDS0  9329 ILLINOIS BELL TEL CO 358      
312-554 2 Chicago Zone 01-Wabash IL CHCGILWBDS0  9329 ILLINOIS BELL TEL CO 358      
312-554 3 Chicago Zone 01-Wabash IL CHCGILWBDS0  9329 ILLINOIS BELL TEL CO 358      
312-554 4 Chicago Zone 01-Wabash IL CHCGILWBDS0  9329 ILLINOIS BELL TEL CO 358      
312-554 5 Chicago Zone 01-Wabash IL CHCGILWBXDZ  984E BANDWIDTH.COM CLEC, LLC - IL 358   2010-03-04   
312-554 6 Chicago Zone 01-Wabash IL DWGVILMCPS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 358   2011-01-05   
312-554 7 Chicago Zone 01-Wabash IL CHCGILWBDS0  9329 ILLINOIS BELL TEL CO 358      
312-554 8 Chicago Zone 01-Wabash IL CHCGILWBDS0  9329 ILLINOIS BELL TEL CO 358      
312-554 9 Chicago Zone 01-Wabash IL ELGNILOTGT5  6529 T-MOBILE USA, INC. 358   2011-01-05   

Last updated: Wed, 18 Jun 2025 02:30:00 UTC

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