Local Calling Guide

Area code/prefix search

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NPA: 857 [Rate centres in NPA 857] [Dial plan for NPA 857]

NXX: 557

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
857-557 A Boston MA CMBRMABETMD  321J HD CARRIER LLC 128      
857-557 0 Boston MA BSTPMALLDS3  892D ONVOY, LLC - MA 128   2023-10-06   
857-557 1 Boston MA CMBRMABEEMD  116E INTRADO COMMUNICATIONS, LLC 128   2019-11-22   
857-557 2 Boston MA   7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 128   2019-12-30   
857-557 3 Boston MA BSTPMALLDS3  892D ONVOY, LLC - MA 128   2020-10-03   
857-557 4 Boston MA BSTPMALLDS3  892D ONVOY, LLC - MA 128   2020-01-16   
857-557 5 Boston MA BSTPMALLDS3  892D ONVOY, LLC - MA 128   2019-11-18   
857-557 6 Boston MA BSTPMALLDS3  892D ONVOY, LLC - MA 128   2020-01-16   
857-557 7 Boston MA BSTPMALLDS3  892D ONVOY, LLC - MA 128   2019-11-18   
857-557 8 Boston MA BSTPMALLDS3  892D ONVOY, LLC - MA 128   2019-11-18   
857-557 9 Boston MA CMBRMABETMD  321J HD CARRIER LLC 128   2019-10-18   

Last updated: Thu, 20 Nov 2025 13:34:34 UTC

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