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.

Switch: PTISTXSPRS0

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
956-761 A Port Isabel TX 9533 SOUTHWESTERN BELL 568      
956-761 0 Port Isabel TX 9533 SOUTHWESTERN BELL 568      
956-761 1 Port Isabel TX 9533 SOUTHWESTERN BELL 568      
956-761 2 Port Isabel TX 9533 SOUTHWESTERN BELL 568      
956-761 3 Port Isabel TX 9533 SOUTHWESTERN BELL 568      
956-761 4 Port Isabel TX 9533 SOUTHWESTERN BELL 568      
956-761 5 Port Isabel TX 9533 SOUTHWESTERN BELL 568      
956-761 6 Port Isabel TX 9533 SOUTHWESTERN BELL 568      
956-761 7 Port Isabel TX 9533 SOUTHWESTERN BELL 568      
956-761 8 Port Isabel TX 9533 SOUTHWESTERN BELL 568      
956-772 A Port Isabel TX 9533 SOUTHWESTERN BELL 568      
956-772 1 Port Isabel TX 9533 SOUTHWESTERN BELL 568      
956-772 9 Port Isabel TX 9533 SOUTHWESTERN BELL 568      

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

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