After studying accountancy at Lancashire University and qualifying as a Chartered Accountant in England, Duncan transferred to Perth in 1987. He worked with KPMG for 28 years, including 17 years as a partner. He led KPMG's Corporate Finance and Forensic Accounting teams in Perth as well as being the Founding National Chairman of KPMG's China Business Practice.
Duncan is a nationally recognised specialist and commentator on Sino Australian business, having led the Australia China Business Council as National President (2013 – 2014) and Western Australian State President (2007 – 2013). He was Chair of the Advisory Committee of the Confucius Institute W.A.
Duncan has extensive experience in leadership positions with not-for-profit organisations including having been the Chair, Deputy Chair and Treasurer of Parkerville Children and Youth Care for over a decade as well as the State President of Amnesty International. He was a prominent member for two Olympics and 2 Commonwealth Games on the Fundraising Committee of the AOC.
Duncan provided strategic advice to the founders of Manna in 2016 and was appointed to the Board in June 2017, becoming Deputy Chair in January 2018.
He is married to Melanie and has two adult sons.