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: SXFLSDCOY0X

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
605-403 A Sioux Falls SD 425J CSC WIRELESS, LLC 640      
605-403 2 Sioux Falls SD 425J CSC WIRELESS, LLC 640   2019-07-20   

Last updated: Sun, 07 Dec 2025 22:02:11 UTC

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