Seiber emigrated to England in 1935 and settled in London, after his marriage in Caterham, Surrey at 169 Stafford Road. He only became a British citizen after the World War II. Seiber taught composition and cello privately while working as a consultant for the subsidiary of Schott in London and composed film music. Michael Tippett invited him to be a professor of composition at Morley College in London, and from 1942 he was on the staff there; he became a teacher of composition, music aesthetics, and music theory. His students included Peter Racine Fricker, Don Banks, Anthony Milner, Hugh Wood, Karel Janovický, Malcolm Lipkin, John Exton, Wally Stott (who later became Angela Morley) and Barry Gray. During this period, he created and trained his choir, the Dorian Singers.