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: 617 [Rate centres in NPA 617] [Dial plan for NPA 617]

NXX: 250

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
617-250 A Cambridge MA CMBRMA01DS5  7135 TC SYSTEMS, INC. 128      
617-250 0 Cambridge MA BSTPMALLDS3  892D ONVOY, LLC - MA 128   2023-07-30   
617-250 1 Cambridge MA CMBRMA01DS5  7135 TC SYSTEMS, INC. 128      
617-250 2 Cambridge MA CMBRMA01DS5  7135 TC SYSTEMS, INC. 128      
617-250 3 Cambridge MA CMBRMA01DS5  7135 TC SYSTEMS, INC. 128      
617-250 4 Cambridge MA CMBRMA01DS5  7135 TC SYSTEMS, INC. 128      
617-250 5 Cambridge MA CMBRMA01DS5  7135 TC SYSTEMS, INC. 128      
617-250 6 Cambridge MA CMBRMA01DS5  7135 TC SYSTEMS, INC. 128      
617-250 7 Cambridge MA CMBRMAORDSG  4018 LEVEL 3 COMMUNICATIONS, LLC - MA 128   2005-03-08   
617-250 8 Cambridge MA CMBRMAORDSG  4018 LEVEL 3 COMMUNICATIONS, LLC - MA 128   2008-02-01   
617-250 9 Cambridge MA CMBRMA01DS5  7135 TC SYSTEMS, INC. 128      

Last updated: Wed, 18 Jun 2025 02:30:00 UTC

Sponsored by: VoIP Much Phone Company

Like this site? We accept donations via PayPal.