Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 303 [Rate centres in NPA 303] [Dial plan for NPA 303]

NXX: 991

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
303-991 A Denver CO DNVRCO37DS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 656      

Last updated: Sun, 07 Dec 2025 22:02:11 UTC

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