He has previously played for Airdrieonians, Wolverhampton Wanderers, Cowdenbeath, Forfar Athletic and Clyde (two spells).
[1] In April 2013, Allan made his debut for Scottish club Airdrie United as a substitute against Livingston in a 2–0 defeat.
[2][3] Still a pupil at Calderside Academy and aged just 14 years and 189 days, Allan became the youngest player to represent a first team in the Scottish Football League,[4] and Britain, breaking the record previously established by Reuben Noble-Lazarus in January 2008;[5] (the British record stood for almost a decade before being broken by Christopher Atherton from Northern Ireland)[6] but the SFL record will never be bettered as the organisation was replaced by the Scottish Professional Football League a few months later.
[9] He signed for Scottish League Two club Cowdenbeath in November 2018, and then moved to Forfar Athletic during August 2020.
[12][13] On 26 January 2023, Allan move to league rivals Falkirk for an undisclosed fee and signed a two-and-a-half-year deal with the Bairns.