Cash made his professional debut on the undercard of Anthony Joshua vs. Dominic Breazeale on 25 June 2016, scoring a four-round points decision (PTS) victory against Yailton Neves at The O2 Arena in London.

[4] After winning his first 9 fights, 6 by stoppage, he faced Stephen Danyo for the vacant WBC International Silver middleweight title on 28 October 2018 at the Copper Box Arena, London.

He rose to his feet before the count of ten but immediately stumbled backwards, prompting referee Marcus McDonnell to call a halt to the contest, awarding the Commonwealth title with a first-round technical knockout (TKO).

[7][8] His second defence—and only fight of 2020—came against former British middleweight champion and world title challenger Jason Welborn on 14 August, at the Matchroom Sport headquarters in Brentwood, Essex.

[9] After nearly a year out of the ring, it was announced on 17 March 2021 that Cash's next fight would take place on 24 April, against reigning British middleweight champion Denzel Bentley.