[citation needed] 2013–2014 Chisholm joined the full-time Harlequins Academy in July 2013 and made his senior debut that same year against Exeter Chiefs in the LV= Cup.

[7] 2020–2021 He scored a try after coming on as a replacement during Harlequins 43-36 defeat of Bristol Bears in the Premiership semi-final, a game in which Quins recovered from 28 points down to win.

[10] In January 2025, having been moved into the second row for the first time while playing for the club, he scored a try in 24–7 against Glasgow Warriors to help Harlequins secure their place in the knockout stages of the 2024–25 Champions Cup.

In December 2013, the Harlequins Number Eight reclaimed the armband in his last U18 international match and led his England U18 side to a convincing 23–3 win over Australia Schoolboys at Harrow School.

James added another when England lost 21–15 to Wales at Colwyn Bay in the opening game of the 2015 Six Nations Under 20s Championship and made his fifth touchdown at this level against Scotland that March.

Chisholm was the BMW Man of the Match in successive games against Scotland and France and said after England clinched the 2015 Six Nations title: “It was amazing but tough at times.