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: CSRKCONMDS0

Remotes:

Switch Switch name Switch type
DCKRCOMARS1  DECKERS  5ER 
LRKSCONMRS1  LARKSPUR  5ER 
NPA-NXX BLOCK Rate Centre Region OCN LATA LIR Eff date Disc date
303-387 A Denver CO 9636 QWEST CORPORATION 656      
303-660 A Denver CO 9636 QWEST CORPORATION 656      
303-663 A Denver CO 9636 QWEST CORPORATION 656      
303-688 A Denver CO 9636 QWEST CORPORATION 656      
303-814 A Denver CO 9636 QWEST CORPORATION 656      
720-433 A Denver CO 9636 QWEST CORPORATION 656      
720-455 A Denver CO 9636 QWEST CORPORATION 656      
720-733 A Denver CO 9636 QWEST CORPORATION 656      

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

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