Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
  • Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information.
  • If you want to search an entire area code regardless of activity, leave both the next and past days fields set to zero.

NPA: 557 [Rate centres in NPA 557] [Dial plan for NPA 557]

NXX: 210

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
557-210 A Ladue MO STLTMOBOAMD  5814 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 520      
557-210 0 Ladue MO   093F ONVOY, LLC - MO 520   2024-07-18   
557-210 1 Ladue MO   093F ONVOY, LLC - MO 520   2024-07-05   
557-210 2 Ladue MO   093F ONVOY, LLC - MO 520   2024-07-05   
557-210 3 Ladue MO   093F ONVOY, LLC - MO 520   2024-07-05   
557-210 4 Ladue MO   5814 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 520   2024-09-28   
557-210 5 Ladue MO   5814 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - MO 520   2024-09-28   
557-210 6 Ladue MO   624H ONVOY SPECTRUM, LLC 520   2023-11-27   
557-210 7 Ladue MO   515J IP HORIZON LLC 520   2023-12-07   
557-210 8 Ladue MO   732J NUSO, LLC 520   2023-12-22   
557-210 9 Ladue MO   732J NUSO, LLC 520   2023-12-22   

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

Sponsored by: BeeVox - Whitelabel Reseller Platform

Like this site? We accept donations via PayPal.