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: 597

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
857-597 A Winthrop MA BSTPMALLDS3  892D ONVOY, LLC - MA 128      
857-597 0 Winthrop MA BSTPMALLOMD  073H TELNYX LLC 128   2021-06-04   
857-597 1 Winthrop MA CMBRMABENMD  624H ONVOY SPECTRUM, LLC 128   2021-11-27   
857-597 2 Winthrop MA BSTPMALLDS3  892D ONVOY, LLC - MA 128   2021-08-14   
857-597 3 Winthrop MA BSTPMALLDS3  892D ONVOY, LLC - MA 128   2021-08-14   
857-597 4 Winthrop MA SOVLMAABBMD  145J TERRA NOVA TELECOM INC. 128   2024-09-09   
857-597 5 Winthrop MA BSTPMALLDS3  892D ONVOY, LLC - MA 128   2021-06-03   
857-597 6 Winthrop MA BSTPMALLDS3  892D ONVOY, LLC - MA 128   2023-11-19   
857-597 7 Winthrop MA BSTPMALLDS3  892D ONVOY, LLC - MA 128   2021-07-10   
857-597 8 Winthrop MA BSTPMALLDS3  892D ONVOY, LLC - MA 128   2021-07-10   
857-597 9 Winthrop MA CMBRMABENMD  624H ONVOY SPECTRUM, LLC 128   2021-11-27   

Last updated: Sun, 26 Jan 2025 15:59:20 UTC

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.