Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
  • Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information.
  • If you want to search an entire area code regardless of activity, leave both the next and past days fields set to zero.

NPA: 312 [Rate centres in NPA 312] [Dial plan for NPA 312]

NXX: 612

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
312-612 A Chicago Zone 01-Canal IL CHCGILCLDS3  9329 ILLINOIS BELL TEL CO 358      
312-612 0 Chicago Zone 01-Canal IL CHCGILWBXDZ  984E BANDWIDTH.COM CLEC, LLC - IL 358   2010-03-04   
312-612 1 Chicago Zone 01-Canal IL CHCGILGMDS7  6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358   2000-09-28   
312-612 2 Chicago Zone 01-Canal IL CHCGILGMDS7  6115 LEVEL 3 COMMUNICATIONS, LLC - IL 358   2000-09-28   
312-612 3 Chicago Zone 01-Canal IL CHCGILCLDS3  9329 ILLINOIS BELL TEL CO 358      
312-612 4 Chicago Zone 01-Canal IL CHCGILCLDS3  9329 ILLINOIS BELL TEL CO 358      
312-612 5 Chicago Zone 01-Canal IL CHCGILCLDS3  9329 ILLINOIS BELL TEL CO 358      
312-612 6 Chicago Zone 01-Canal IL CHCGILCLDS3  9329 ILLINOIS BELL TEL CO 358   2000-10-24   
312-612 7 Chicago Zone 01-Canal IL CHCGILCLDS3  9329 ILLINOIS BELL TEL CO 358   2000-10-24   
312-612 8 Chicago Zone 01-Canal IL CHCGILCLDS3  9329 ILLINOIS BELL TEL CO 358   2000-10-24   
312-612 9 Chicago Zone 01-Canal IL CHCGILWBXDZ  984E BANDWIDTH.COM CLEC, LLC - IL 358   2010-03-04   

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

Sponsored by: LES.NET

Like this site? We accept donations via PayPal.