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: 618 [Rate centres in NPA 618] [Dial plan for NPA 618]

NXX: 400

NPA-NXX BLOCK Rate Centre Region Switch OCN LATA LIR Eff date Disc date
618-400 A Millstadt IL STLSMOWQDS2  224C ONVOY, LLC 520      
618-400 0 Millstadt IL   224C ONVOY, LLC 520   2018-02-04   
618-400 1 Millstadt IL   073H TELNYX LLC 520   2020-07-16   
618-400 2 Millstadt IL   224C ONVOY, LLC 520   2021-04-24   
618-400 3 Millstadt IL   624H ONVOY SPECTRUM, LLC 520   2025-01-04   
618-400 4 Millstadt IL   224C ONVOY, LLC 520   2019-07-29   
618-400 5 Millstadt IL   224C ONVOY, LLC 520   2019-07-29   
618-400 6 Millstadt IL   224C ONVOY, LLC 520   2021-04-24   
618-400 7 Millstadt IL   508J CENTURYLINK COMMUNICATIONS, LLC 520   2016-01-22   
618-400 8 Millstadt IL   495J STRATUS NETWORKS 520   2020-11-22   
618-400 9 Millstadt IL   075A DELTA COMMS, LLC DBA CLEARWAVE COMMUNICATIONS - IL 520   2021-02-28   

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

Sponsored by: ISP Telecom

Like this site? We accept donations via PayPal.