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: 203

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
312-203 A Chicago Zone 01-Wabash IL BURGILAHGT3  6534 NEW CINGULAR WIRELESS PCS, LLC - IL 358      

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

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