In the King's 2023 Birthday Honours he was appointed Member of the Order of the British Empire for services to wheelchair rugby league football.

[2] During his second combat tour, in 2009, six years into his service, an IED detonated when Simpson was on routine patrol resulting in him losing both his legs.

[10] In 2021, the first season after the COVID-19 pandemic, Leeds retain the League Leaders' Shield and the Challenge Cup[11] in addition to beating Leyland Warriors 52–36 in the Grand Final to complete the first wheelchair treble.

[13][14] On 13 January 2023, Simpson retired as a player from wheelchair rugby league; joining the coaching staff of Leeds Rhinos, the club in which he spent his entire career.

[15] He played in his first Wheelchair Rugby League World Cup at the 2017 tournament[23] where England finished runners-up losing to France in the final.