Mark began his business career as a shipbroker, before becoming joint owner of a marine consultancy and ship management company, which was sold to Aminex plc. Following the sale, he ran Aminex’s procurement and oilfield service business, Amossco Ltd. In 2002, he joined HSBC Insurance Brokers as a Business Development Director, eventually becoming Head of Energy, then, Head of Africa, before HSBC sold its insurance subsidiary in March 2010.

Mark then established Samphire & Associates Ltd, a consultancy and advisory services business focused on African related businesses. He served on the board of a range of companies including Britain Nigeria Business Council (2007 to 2009), the Business Council for Africa (2009 to 2015), Resolution Insurance (2014 to 2015), Phoenix Africa Development Co Ltd (2010 to 2019), Leon Africa (2012 to 2016), and on the Advisory Board of South African Broad-Based BEE, woman owned Moshe Capital (2016 to 2021). Mark was also Mentor for Senegal based Femmes Africa Solidarité (2011 to 2014) and specifically to a black woman farmer, a beneficiary of the South African Government’s Land Reform & Rural Development Programme. In November 2019, Mark was appointed to serve as non-executive Chairman of the Board of Directors of VSA Capital. And in December 2023, Mark was appointed Chairman of AIM listed EnergyPathways plc.

Since June 2020 Mark has been approved by the FCA to perform SMF9 Chair of the Governing Body function.