In 2015, he was ranked in the Sunday Times Rich List, with his net worth reported as being £320 million. He notably founded businesses in his teens, filing for bankruptcy in 2003 as a result of the Dot-com bubble. The following year, Windhorst co-founded the Sapinda Group. Following restructuring, Sapinda Holding BV, founded in 2009, is the group's parent company. Windhorst is its Non-Executive Chairman.
