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.
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NPA: 737 [Rate centres in NPA 737] [Dial plan for NPA 737]

NXX: 421

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
737-421 A Rockdale TX   6529 T-MOBILE USA, INC. 558   2025-07-21   
737-421 0 Rockdale TX   004F BANDWIDTH.COM CLEC, LLC - TX 558   2025-12-13   
737-421 1 Rockdale TX   793K TWC IP ENABLED SERVICES, LLC 558   2025-11-02   
737-421 2 Rockdale TX   6506 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TX 558   2025-10-07   
737-421 8 Rockdale TX   6529 T-MOBILE USA, INC. 558   2025-07-21   
737-421 9 Rockdale TX   6529 T-MOBILE USA, INC. 558   2025-07-21   

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

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