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: 222

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
557-222 A St Louis MO STLSMOGZTMD  616J LEAP TELECOM, LLC 520      
557-222 0 St Louis MO   7218 TELEPORT COMMUNICATIONS AMERICA, LLC - MO 520   2023-06-19   
557-222 1 St Louis MO   093F ONVOY, LLC - MO 520   2024-05-12   
557-222 2 St Louis MO   616J LEAP TELECOM, LLC 520   2023-06-18   
557-222 3 St Louis MO   732J NUSO, LLC 520   2024-04-12   
557-222 4 St Louis MO   732J NUSO, LLC 520   2024-04-12   
557-222 5 St Louis MO   732J NUSO, LLC 520   2024-08-19   
557-222 6 St Louis MO   732J NUSO, LLC 520   2024-08-19   
557-222 7 St Louis MO   093F ONVOY, LLC - MO 520   2025-01-06   
557-222 8 St Louis MO   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 520   2025-08-02   
557-222 9 St Louis MO   6534 NEW CINGULAR WIRELESS PCS, LLC - IL 520   2023-09-04   

Last updated: Tue, 13 Jan 2026 21:50:02 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.