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: 347

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
331-347 A Wheaton IL   224C ONVOY, LLC 358   2026-09-18   
331-347 0 Wheaton IL   224C ONVOY, LLC 358   2026-09-18   
331-347 1 Wheaton IL   224C ONVOY, LLC 358   2026-09-21   

Last updated: Tue, 01 Sep 2026 00:40:05 UTC

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