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: 242

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
557-242 A St Louis MO   093F ONVOY, LLC - MO 520   2025-11-15   
557-242 0 St Louis MO   093F ONVOY, LLC - MO 520   2025-11-15   
557-242 1 St Louis MO   093F ONVOY, LLC - MO 520   2025-11-15   
557-242 2 St Louis MO   093F ONVOY, LLC - MO 520   2025-11-15   
557-242 3 St Louis MO   093F ONVOY, LLC - MO 520   2025-11-15   
557-242 6 St Louis MO   7218 TELEPORT COMMUNICATIONS AMERICA, LLC - MO 520   2025-12-01   
557-242 8 St Louis MO   093F ONVOY, LLC - MO 520   2025-11-17   
557-242 9 St Louis MO   093F ONVOY, LLC - MO 520   2025-11-17   

Last updated: Thu, 20 Nov 2025 13:34:34 UTC

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