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: DNVRCOSEDS0

NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
303-300 A Denver CO 9636 QWEST CORPORATION 656      
303-504 A Denver CO 9636 QWEST CORPORATION 656      
303-512 A Denver CO 9636 QWEST CORPORATION 656      
303-584 A Denver CO 9636 QWEST CORPORATION 656      
303-639 A Denver CO 9636 QWEST CORPORATION 656      
303-691 A Denver CO 9636 QWEST CORPORATION 656      
303-692 A Denver CO 9636 QWEST CORPORATION 656      
303-753 A Denver CO 9636 QWEST CORPORATION 656      
303-756 A Denver CO 9636 QWEST CORPORATION 656      
303-757 A Denver CO 9636 QWEST CORPORATION 656      
303-758 A Denver CO 9636 QWEST CORPORATION 656      
303-759 A Denver CO 9636 QWEST CORPORATION 656      
303-782 A Denver CO 9636 QWEST CORPORATION 656      
720-242 A Denver CO 9636 QWEST CORPORATION 656      
720-524 A Denver CO 9636 QWEST CORPORATION 656      

Last updated: Tue, 13 Jan 2026 21:50:02 UTC

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