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: 815 [Rate centres in NPA 815] [Dial plan for NPA 815]

NXX: 428

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
815-428 A Martinton IL MTTNILXARS0  1015 FRONTIER NORTH, INC. - IL 358      
815-428 0 Martinton IL   224C ONVOY, LLC 358   2020-07-11   
815-428 1 Martinton IL   224C ONVOY, LLC 358   2019-08-24   
815-428 4 Martinton IL   984E BANDWIDTH.COM CLEC, LLC - IL 358   2012-04-15   
815-428 5 Martinton IL   984E BANDWIDTH.COM CLEC, LLC - IL 358   2015-09-27   
815-428 6 Martinton IL   508J CENTURYLINK COMMUNICATIONS, LLC 358   2015-06-25   
815-428 7 Martinton IL   1015 FRONTIER NORTH, INC. - IL 358      
815-428 9 Martinton IL   073H TELNYX LLC 358   2020-07-16   

Last updated: Tue, 13 Jan 2026 21:50:02 UTC

Sponsored by: FiberConX Communications Ltd.

Like this site? We accept donations via PayPal.