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: DNVRCOMA32Z

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NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
983-777 8 Denver CO 321J HD CARRIER LLC 656   2023-12-04   
983-888 1 Denver CO 321J HD CARRIER LLC 656   2023-08-05   
983-999 1 Denver CO 321J HD CARRIER LLC 656   2023-10-08   
983-999 3 Denver CO 321J HD CARRIER LLC 656   2023-10-08   

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Last updated: Sat, 01 Aug 2026 03:19:33 UTC

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