 After a successful two-year trial a contract was placed with STC for the provision of £15million of TXE4 equipment in June 1971.The first production TXE4 was installed in 1973 at Rectory, a Birmingham area exchange at Sutton Coldfield, and brought into service on 28 February 1976.TXE4 is sometimes known as TXE4RD where the RD stood for Rectory Design.