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: 433

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
617-433 A Milton MA CMBRMA01DS5  7135 TC SYSTEMS, INC. 128      
617-433 0 Milton MA CMBSMA01AMD  4036 NEW CINGULAR WIRELESS PCS, LLC - DC 128   2013-01-21   
617-433 1 Milton MA CATNMAAKPS0  7229 MCIMETRO ACCESS TRANSMISSION SERVICES LLC 128   2006-09-30   
617-433 2 Milton MA   829J PAETEC ITEL, LLC 128      
617-433 3 Milton MA CMBRMA01DS5  7135 TC SYSTEMS, INC. 128      
617-433 4 Milton MA   829J PAETEC ITEL, LLC 128   2004-10-15   
617-433 5 Milton MA BSTPMALLDS3  892D ONVOY, LLC - MA 128   2010-04-07   
617-433 6 Milton MA CMBRMAMQDS3  316E YMAX COMMUNICATIONS CORP. - MA 128   2009-08-21   
617-433 7 Milton MA BSTNMABLOMD  990E BANDWIDTH.COM CLEC, LLC - MA 128   2010-06-26   
617-433 8 Milton MA BSTNMABLOMD  990E BANDWIDTH.COM CLEC, LLC - MA 128   2010-11-15   
617-433 9 Milton MA BSTNMABLOMD  990E BANDWIDTH.COM CLEC, LLC - MA 128   2012-12-22   

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

Sponsored by: Callcentric - VoIP Internet phone service

Like this site? We accept donations via PayPal.