Maidment started playing rugby at Haywards Heath RFC while living in Sussex. He played in their colts team[6] as well as making the senior 1st XV.[7] He played for Haywards Heath in National League 3 London & SE. When he was 16, he was selected to play for Sussex.[8] While playing underage rugby at Haywards Heath he also played for Brighton College. While at university, Maidment was signed by London Wasps as part of a link-up with the University of Cambridge in 2010.[9] He played for London Wasps in their rugby sevens team and their "A" team. In 2011, after a recommendation from London Wasps, Maidment moved to Moseley Rugby Football Club and made his debut for them in the RFU Championship against Esher RFC.[4] In 2011, a day after his graduation from Cambridge, Maidment moved to Cornish Pirates.[10]
In 2013, Maidment moved to Jersey along with fellow Cornish Pirates players Aaron Penberthy and Grant Pointer.[8] During pre-season, he was sent off against Coventry R.F.C. and was banned by the Rugby Football Union for a week.[11] The ban was initially meant to be served during a friendly against French club, Le Rheu; however, this match did not go ahead. Jersey failed to inform the RFU and its officials that the ban was not served, and then fielded Maidment in their next match, against Plymouth Albion in the RFU Championship.[11] As a result, Maidment and Jersey were charged by the RFU for "failure to act towards the RFU with utmost good faith and/or conduct prejudicial to the interests of the Union and/or the Game".[11] The charge against Maidment was later dropped, but Jersey were fined £5,000 and deducted two RFU Championship points.[11]
While at university, Maidment represented Cambridge in The Varsity Match at Twickenham Stadium against Oxford University.[12] Maidment was also selected to play for England Students.[4] In 2011, Maidment was invited to play for the Barbarians against Bedford Blues, a match which the Barbarians won.[13]