Local Calling Guide

Area code/prefix search

Search area code/prefix (NPA/NXX)
  • Effective date searches are available only for US area codes. Our sources for non-US NPA-NXX data do not provide this information.
  • If you want to search an entire area code regardless of activity, leave both the next and past days fields set to zero.

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

NXX: 491

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
857-491 A Boston MA BSTPMALLBMD  814J LIGHTPATH OF NEW ENGLAND 128      
857-491 0 Boston MA   990E BANDWIDTH.COM CLEC, LLC - MA 128   2022-07-29   
857-491 1 Boston MA   892D ONVOY, LLC - MA 128   2022-05-05   
857-491 2 Boston MA   892D ONVOY, LLC - MA 128   2022-05-05   
857-491 3 Boston MA   892D ONVOY, LLC - MA 128   2022-05-05   
857-491 4 Boston MA   892D ONVOY, LLC - MA 128   2022-04-07   
857-491 5 Boston MA   814J LIGHTPATH OF NEW ENGLAND 128   2021-11-07   
857-491 6 Boston MA   814J LIGHTPATH OF NEW ENGLAND 128   2021-11-07   
857-491 7 Boston MA   892D ONVOY, LLC - MA 128   2022-05-05   
857-491 8 Boston MA   892D ONVOY, LLC - MA 128   2022-09-30   
857-491 9 Boston MA   892D ONVOY, LLC - MA 128   2024-02-24   

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

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.