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: 374

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
312-374 A Chicago Zone 01-Lakeshore IL CHCGILLRDS0  9329 ILLINOIS BELL TEL CO 358      
312-374 0 Chicago Zone 01-Lakeshore IL CHCGILLRDS0  9329 ILLINOIS BELL TEL CO 358      
312-374 1 Chicago Zone 01-Lakeshore IL CHCGILNEXJX  318J COMCAST IP PHONE, LLC 358   2012-12-31   
312-374 2 Chicago Zone 01-Lakeshore IL CHCGILWUX6X  460K FIRST COMMUNICATIONS, LLC 358   2013-01-04   
312-374 3 Chicago Zone 01-Lakeshore IL CHCGILNEXJX  318J COMCAST IP PHONE, LLC 358   2012-12-31   
312-374 4 Chicago Zone 01-Lakeshore IL CHCGILNEXJX  318J COMCAST IP PHONE, LLC 358   2014-01-11   
312-374 5 Chicago Zone 01-Lakeshore IL CHCGILDTKMD  5447 ACCESS ONE, INC. - IL 358   2014-01-12   
312-374 6 Chicago Zone 01-Lakeshore IL CHCGIL24DS6  224C ONVOY, LLC 358   2013-12-23   
312-374 7 Chicago Zone 01-Lakeshore IL CHCGILLRDS0  9329 ILLINOIS BELL TEL CO 358      
312-374 8 Chicago Zone 01-Lakeshore IL CHCGILNEXJX  318J COMCAST IP PHONE, LLC 358   2015-01-08   
312-374 9 Chicago Zone 01-Lakeshore IL CHCGILLRDS0  9329 ILLINOIS BELL TEL CO 358      

Last updated: Sat, 05 Apr 2025 03:03:23 UTC

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