Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 840 [Rate centres in NPA 840] [Dial plan for NPA 840]

NXX: 289

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
840-289 A Diamond Bar CA   649C ONVOY, LLC - CA 730   2026-09-11   
840-289 0 Diamond Bar CA   649C ONVOY, LLC - CA 730   2026-09-11   

Last updated: Sat, 01 Aug 2026 03:19:33 UTC

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