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

NXX: 250

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
737-250 A Martindale TX SMRCTXXAYMD  903C ONVOY, LLC - TX 558      
737-250 0 Martindale TX SMRCTXXAYMD  903C ONVOY, LLC - TX 558   2018-04-22   
737-250 1 Martindale TX AUSTTXGRX3Y  073H TELNYX LLC 558   2018-09-17   
737-250 2 Martindale TX AUSTTXUH5MD  6114 LEVEL 3 COMMUNICATIONS, LLC - TX 558   2018-04-23   
737-250 3 Martindale TX AUSTTXGRDS6  177F PEERLESS NETWORK OF TEXAS, LLC - TX 558   2018-11-16   
737-250 5 Martindale TX AUSTTXGR46Z  158H INVOXIO INCORPORATED 558   2018-07-29   
737-250 6 Martindale TX SMRCTXXAYMD  903C ONVOY, LLC - TX 558   2020-08-16   
737-250 7 Martindale TX SMRCTXXAYMD  903C ONVOY, LLC - TX 558   2020-08-16   
737-250 8 Martindale TX SMRCTXXAYMD  903C ONVOY, LLC - TX 558   2020-08-16   
737-250 9 Martindale TX SMRCTXXAYMD  903C ONVOY, LLC - TX 558   2020-11-23   

Last updated: Sat, 15 Nov 2025 03:38:44 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.