In January 2011, Cahn stepped down after five years in charge of UK Trade & Investment, the government department that promotes exports and attracts foreign direct investment. Prime Minister, David Cameron, said: "Andrew has been a wonderful chief executive of UK Trade & Investment and a fantastic ambassador for the UK. He has been central to the Government’s efforts to make Britain an attractive place to invest and to sell Britain to the world."
He was previously a trustee of the Arvon Foundation, a member of the Government's Financial Services Trade and Investment Board, Board member of CityUK, Chair of the City of London's International Trade and Investment Group, a member of the Advisory Council of the Rector of the University of the Arts, is an Association Member of BUPA and was a member of the Governing Board of Business for New Europe. He has also served as trustee of the Royal Botanic Gardens Kew, where he was Chairman of their Audit Committee, and of Japan Society. Cahn was chair of WWF (UK), a member of the global Board of WWF and Chair of the Audit Committee from April 2014 -June 2020.[7]
Cahn encountered controversy in January 2011, when an internal email he had sent saying the FCO wished to find ways to spend up to its 2010/11 budget ceiling, was leaked to the Daily Mail. In the email, Cahn said: "The FCO is heading for an underspend and wants to get money out of the door."[9]