Addy was employed by Société Commerciale de l'Ouest Africain (S.C.O.A.), where he worked for two and a half years at the Head Office in Accra. In July 1949, he enlisted in the Army as an Education Instructor and later became a Sergeant. Addy served with the second and fourth battalions, and also joined the UN Forces in the Congo, during the Congo crisis in 1963. In March 1966, he was appointed Commanding Officer of the first battalion. That same year, he was made Chairman of the Western Regional Administrative Committee (Regional Minister) and on 4 April 1967, he was made Chairman of the Ashanti Regional Administrative Committee, assuming office on 1 May 1967. He was succeeded by G. K. Yarboi.