British United Airways placed a launch order for 10 of the new jets, then known as the BAC-111, in May 1961. The new aircraft took to the skies for the first time on August 20 1963, while the first production Series 200 first flew on December 19 1963. The BAC-111 entered service on April 6 1965.

The last UK built One-Eleven (by this time a British Aerospace product) flew in 1982, by which time production was progressively being transferred to Bucuresti in Romania where nine were built as the Rombac 1-11.