After serving during
World War I as a Lieutenant with the
London Rifle Brigade, Jopson entered the Foreign Service in 1920. He served as Vice-Consul successively in Chicago (1920–1923); Colon and Panama City (1923–1926), and Cologne (1926–1929). He was
Second Secretary and Vice-Consul at Montevideo (1929–30) and acted as Charge d'Affaires, Montevideo (1930). Then he was Commercial Secretary in Buenos Aires (1930–1933), and in Helsingfors (1933–1938). From 1939 to 1940 he was Director of the Foreign Division at the
Department of Overseas Trade and was seconded to serve as UK
Trade Commissioner at Montreal, Canada. In 1940 he acted as representative of the
Children's Overseas Reception Board. From 1948 to 1953 he served as UK Trade Commissioner in Canada and Economic Adviser to the UK High Commissioner at Ottawa. Jopson served as Ambassador to Colombia from 1953 to 1955. He was instrumental in the founding of the British School in Bogata. He served as Ambassador to Uruguay from 1955 to 1957. When he died in Montevideo while in office, the Uruguayan Government at his funeral there gave him the honours due to a Minister of State. == Personal life and death ==