Allen is a Fellow of the Institute of Chartered Accountants in England and Wales, of the Marketing Institute of Singapore and the Singapore Human Resources Institute. He has extensive experience in Financial Services, Industry and Management Consultancy, whose roles included Managing Director of OCBC bank and Great Eastern Life, Chairman of CSA Singapore TEC , and is the Chairman and Director of several public-listed and private companies in Singapore and overseas, as well as being a member of several government, professional and charitable committees.