He attended University of Adelaide, graduating in 1961 with a Bachelor of Economics with honours.
Codd was appointed to his first Secretary role in 1981, becoming haed of the Department of Industrial Relations. Between 1985 and 1986 Codd served as Secretary of the Department of Community Services. In 1986 he was appointed Department of the Prime Minister and Cabinet Secretary.
In 1987 he worked with Prime Minister Bob Hawke to introduce massive reform changes to the public service, creating "super ministry" departments.
Codd did note potential disadvantages of the machinery of government changes, including that there was potential for "bunker mentality" to continue. Codd retired from the public service in December 1991, his appointment was terminated by an Executive Council meeting on 27 December that year.
After his retirement from the Department of the Prime Minister and Cabinet, Codd joined consultancy firm Coopers and Lybrand. He was also appointed to the board of Qantas in 1992, prior to the airline"s privatization, and served 16 years retiring in 2008.
Between 1997 and 2009 he was Chancellor of the University of Wollongong, retiring in September 2009.