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: 303 [Rate centres in NPA 303] [Dial plan for NPA 303]

NXX: 856

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
303-856 A Denver CO DNVTCO56DS8  6118 LEVEL 3 COMMUNICATIONS, LLC - CO 656      
303-856 0 Denver CO DNVTCO56DS8  6118 LEVEL 3 COMMUNICATIONS, LLC - CO 656      
303-856 1 Denver CO DNVTCO56DS8  6118 LEVEL 3 COMMUNICATIONS, LLC - CO 656      
303-856 2 Denver CO DNVTCO56DS8  6118 LEVEL 3 COMMUNICATIONS, LLC - CO 656      
303-856 3 Denver CO DNVRCOMA39Z  318J COMCAST IP PHONE, LLC 656      
303-856 4 Denver CO DNVRCOII3MD  6529 T-MOBILE USA, INC. 656      
303-856 5 Denver CO DNVRCOII3MD  6529 T-MOBILE USA, INC. 656      
303-856 6 Denver CO DNVRCOII3MD  6529 T-MOBILE USA, INC. 656      
303-856 7 Denver CO DNVRCOMA39Z  318J COMCAST IP PHONE, LLC 656      
303-856 8 Denver CO DNVRCOII3MD  6529 T-MOBILE USA, INC. 656      
303-856 9 Denver CO DNVTCOZIDS1  026D ONVOY, LLC - CO 656      

Last updated: Wed, 20 Nov 2024 21:20:06 UTC

Sponsored by: BeeVox - Whitelabel Reseller Platform

Like this site? We accept donations via PayPal.