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: 504

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
857-504 A Boston MA CMBRMAORDSG  4018 LEVEL 3 COMMUNICATIONS, LLC - MA 128   2024-01-03   
857-504 1 Boston MA SOVLMAABDS2  268F PEERLESS NETWORK OF MASSACHUSETTS, LLC - MA 128   2015-11-07   
857-504 2 Boston MA CMBRMAORDSG  4018 LEVEL 3 COMMUNICATIONS, LLC - MA 128   2016-02-19   
857-504 3 Boston MA CMBRMAORDS0  7199 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MA 128   2015-11-10   
857-504 4 Boston MA NRTNMAAACM4  5562 METROPCS, INC. 128   2016-02-13   
857-504 5 Boston MA NRTNMAAACM4  5562 METROPCS, INC. 128   2016-02-13   
857-504 6 Boston MA CMBRMAORDSG  4018 LEVEL 3 COMMUNICATIONS, LLC - MA 128   2016-02-19   
857-504 7 Boston MA CMBRMAORDS0  7199 MCIMETRO ACCESS TRANSMISSION SERVICES LLC - MA 128   2016-03-09   
857-504 8 Boston MA SOVLMAABDS2  268F PEERLESS NETWORK OF MASSACHUSETTS, LLC - MA 128   2015-12-06   
857-504 9 Boston MA BSTNMACOVMD  4084 PAETEC COMMUNICATIONS, INC. - MA 128   2016-02-04   

Last updated: Fri, 22 Mar 2024 03:02:44 UTC

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.