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: 666

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
840-666 A Fontana CA LSANCAJWIMD  965H FRACTEL, LLC 730      
840-666 0 Fontana CA   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2021-04-08   
840-666 1 Fontana CA   939H COMMIO, LLC 730   2021-09-16   
840-666 2 Fontana CA   939H COMMIO, LLC 730   2021-09-16   
840-666 3 Fontana CA   939H COMMIO, LLC 730   2021-09-16   
840-666 4 Fontana CA   939H COMMIO, LLC 730   2021-09-16   
840-666 5 Fontana CA   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2021-03-31   
840-666 6 Fontana CA   965H FRACTEL, LLC 730   2021-02-25   
840-666 7 Fontana CA   6010 NEW CINGULAR WIRELESS PCS, LLC 730   2021-03-31   
840-666 8 Fontana CA   6529 T-MOBILE USA, INC. 730   2021-03-29   
840-666 9 Fontana CA   6529 T-MOBILE USA, INC. 730   2021-03-29   

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

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