As a past winner of the Formula Ford Festival and British Formula Renault series, Duncan has since shown his versatility in a wide range of series including victories and podiums in GT Asia, Superleague Formula, and British GT.
In 2019 Duncan participated in the Michelin Le Mans Cup with Lanan Racing, becoming vice-champion in the LMP3 category with three wins and four podiums to his name.
Duncan signed with United Autosport in 2020, racing with the team in the European Le Mans Series. Over the six rounds, Tappy accumulated 46.5 points, awarding him sixth in the championship standings.
This year, Duncan will continue with United Autosport hoping to improve on his 2020 performance in the ELMS. In addition to this series, the British driver will also return to LMP3 and appear in the Asian LeMans Team.