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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Switch: DLLATX37DS6

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NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
972-999 0 Irving TX 6114 LEVEL 3 COMMUNICATIONS, LLC - TX 552      
972-999 1 Irving TX 6114 LEVEL 3 COMMUNICATIONS, LLC - TX 552      
972-999 2 Irving TX 6114 LEVEL 3 COMMUNICATIONS, LLC - TX 552      
972-999 4 Irving TX 6114 LEVEL 3 COMMUNICATIONS, LLC - TX 552      
972-999 8 Irving TX 6114 LEVEL 3 COMMUNICATIONS, LLC - TX 552      

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

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