Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 331 [Rate centres in NPA 331] [Dial plan for NPA 331]

NXX: 344

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
331-344 A West Chicago IL   224C ONVOY, LLC 358   2026-03-26   
331-344 0 West Chicago IL   224C ONVOY, LLC 358   2026-03-26   
331-344 4 West Chicago IL   145J TERRA NOVA TELECOM INC. 358   2026-03-29   

Last updated: Sat, 21 Mar 2026 23:53:39 UTC

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