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: 507 [Rate centres in NPA 507] [Dial plan for NPA 507]

NXX: 904

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
507-904 A Hayfield MN ROCHMNHI21Z  490J BOOST SUBSCRIBERCO L.L.C. 620      
507-904 0 Hayfield MN ROCHMNROXRX  073H TELNYX LLC 620   2023-04-06   
507-904 1 Hayfield MN ROCHMNHI9MD  939H COMMIO, LLC 620   2023-10-20   
507-904 7 Hayfield MN ROCHMNROUMD  184D ONVOY, LLC - MN 620   2023-04-06   
507-904 8 Hayfield MN ROCHMNHI21Z  490J BOOST SUBSCRIBERCO L.L.C. 620   2023-04-05   

Last updated: Wed, 04 Mar 2026 03:00:52 UTC

Sponsored by: VoIP Much Phone Company

Like this site? We accept donations via PayPal.