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: 720 [Rate centres in NPA 720] [Dial plan for NPA 720]

NXX: 423

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
720-423 A Denver CO DNVRCOCHDS0  9636 QWEST CORPORATION 656      
720-423 0 Denver CO DNVRCOCHDS0  9636 QWEST CORPORATION 656   2004-06-15   
720-423 1 Denver CO DNVRCOCHDS0  9636 QWEST CORPORATION 656   2004-06-15   
720-423 2 Denver CO DNVRCOCHDS0  9636 QWEST CORPORATION 656   2004-06-15   
720-423 3 Denver CO DNVRCOCHDS0  9636 QWEST CORPORATION 656   2004-06-15   
720-423 4 Denver CO DNVRCOCHDS0  9636 QWEST CORPORATION 656   2004-07-15   
720-423 5 Denver CO DNVRCOCHDS0  9636 QWEST CORPORATION 656   2004-06-15   
720-423 6 Denver CO DNVRCOCHDS0  9636 QWEST CORPORATION 656   2004-06-15   
720-423 7 Denver CO DNVRCOCHDS0  9636 QWEST CORPORATION 656   2004-06-15   
720-423 8 Denver CO DNVRCOCHDS0  9636 QWEST CORPORATION 656   2004-07-15   
720-423 9 Denver CO DNVRCOCHDS0  9636 QWEST CORPORATION 656   2004-06-15   

Last updated: Tue, 16 Apr 2024 01:38:01 UTC

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