He made his first appearances in single-seater racing in 2006, gaining experience in Formula BMW. Since then his career path has seen him rise through the ranks in various singleseater
series. At the same time, Sims also began competing in endurance races in 2012. He competed in the European Le Mans Series in an LMP2 prototype.
2014 was the first year Sims took part in the Nürburgring 24 Hours for BMW Motorsport. He also competed for Team Ecurie Ecosse in the Blancpain Endurance Series and the British GT Championship. Sims and his team-mates produced a spectacular fightback at the 24 Hours of Spa-Francorchamps in 2015, when he came through from 20th to seventh overall to present the Ecurie Ecosse team with third place in the fiercely-competitive Pro-Am class.
In 2016, it was Sims who won the race in the Ardennes together with Maxime Martin and Philipp Eng at the wheel of the BMW M6 GT3. He also drove for ROWE Racing in the Blancpain GT Series together with Eng. In 2017, he will share the cockpit of the BMW M6 GTLM with Bill Auberlen.