Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
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NPA: 857 [Rate centres in NPA 857] [Dial plan for NPA 857]

NXX: 388

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
857-388 A Somerville MA SOVLMAAB6MD  939H COMMIO, LLC 128      
857-388 0 Somerville MA   939H COMMIO, LLC 128   2021-11-25   
857-388 1 Somerville MA   939H COMMIO, LLC 128   2021-11-25   
857-388 2 Somerville MA   939H COMMIO, LLC 128   2021-11-25   
857-388 3 Somerville MA   624H ONVOY SPECTRUM, LLC 128   2021-11-27   
857-388 4 Somerville MA   892D ONVOY, LLC - MA 128   2022-03-21   
857-388 5 Somerville MA   624H ONVOY SPECTRUM, LLC 128   2022-01-15   
857-388 6 Somerville MA   624H ONVOY SPECTRUM, LLC 128   2022-01-15   
857-388 7 Somerville MA   892D ONVOY, LLC - MA 128   2022-03-21   
857-388 8 Somerville MA   892D ONVOY, LLC - MA 128   2021-11-27   
857-388 9 Somerville MA   892D ONVOY, LLC - MA 128   2023-08-17   

Last updated: Thu, 29 Jan 2026 14:35:03 UTC

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