Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 831 [Rate centres in NPA 831] [Dial plan for NPA 831]

NXX: 921

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
831-921 A Tres Pinos CA SLNSCA01XXX  8826 LEVEL 3 COMMUNICATIONS, LLC - CA 736      
831-921 0 Tres Pinos CA   145J TERRA NOVA TELECOM INC. 736   2024-12-31   
831-921 1 Tres Pinos CA   373F PEERLESS NETWORK OF CALIFORNIA, LLC - CA 736   2016-03-05   
831-921 2 Tres Pinos CA   649C ONVOY, LLC - CA 736   2019-07-28   
831-921 3 Tres Pinos CA   649C ONVOY, LLC - CA 736   2019-07-28   

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

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