With Sussex's first-choice wicket-keeper, Matt Prior, on England duty in the 2013 Ashes series and regular back-up Ben Brown injured with a broken finger, Jackson made his competitive debut for the club in a Friends Life t20 match against the Essex Eagles on 21 July 2013. Although he did not bat and Sussex lost by seven wickets, he made an impression by stumping Greg Smith, Hamish Rutherford and Ravi Bopara for Sussex's only wickets of the match. He appeared in a total of six limited overs matches for Sussex in 2013.