Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 557 [Rate centres in NPA 557] [Dial plan for NPA 557]

NXX: 257

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
557-257 A Creve Coeur MO   093F ONVOY, LLC - MO 520   2026-08-29   
557-257 0 Creve Coeur MO   093F ONVOY, LLC - MO 520   2026-08-29   
557-257 1 Creve Coeur MO   093F ONVOY, LLC - MO 520   2026-08-29   
557-257 2 Creve Coeur MO   093F ONVOY, LLC - MO 520   2026-08-29   
557-257 7 Creve Coeur MO   993E BANDWIDTH.COM CLEC, LLC - MO 520   2026-11-07   
557-257 8 Creve Coeur MO   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 520   2026-11-06   
557-257 9 Creve Coeur MO   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 520   2026-11-06   

Last updated: Sat, 10 Oct 2026 15:24:20 UTC

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