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: 450

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
737-450 A Lockhart TX AUSTTXGR03Z  903C ONVOY, LLC - TX 558   2026-02-07   
737-450 0 Lockhart TX AUSTTXGR03Z  903C ONVOY, LLC - TX 558   2026-02-07   
737-450 1 Lockhart TX AUSUTX78AMD  6506 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - TX 558   2026-02-09   

Last updated: Thu, 16 Jul 2026 02:21:55 UTC

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