Born in Hitchin, Allinson began his career with Colchester United as an apprentice in the summer of 1974 and made his debut later in the season, coming on as a substitute for Jimmy Lindsay against Bobby Charlton's Preston North End on 19 April 1975.
Colchester boasted a powerful strike force of Roy McDonough, Kevin Bremner, Tony Adcock and Allinson, who scored 43 league goals in just two seasons.
Allinson was valued in the region of £100,000 to Colchester, but an administration error cost the club dearly when his future benefits and bonuses were erroneously entered as less than his previous contract, entitling the player to a free-transfer.
[2] Allinson's debut for Arsenal came in a shock League Cup defeat to Walsall on 29 November 1983, signalling the end of Terry Neill's tenure as manager of the club.
He scored three goals in 32 league games for Luton, before rejoining Colchester United in December 1988 on a free transfer.
[2] Allinson was tasked with having to help save Colchester from relegation from the Football League to the Conference by caretaker manager Steve Foley, and under new manager Jock Wallace, United clawed their way back up from the bottom of the league table, with Allinson scoring seven crucial goals to stave off the threat of relegation in the 1988–89 season.
Upon taking on the Chairmanship of the Northamptonshire club, Evans dismissed the managerial duo of Bryn Gunn and Gerry McElhinney in favour of Allinson but he resigned just a day after his appointment when he tendered his resignation after returning home from his first training session where he was introduced to the players.
"[citation needed] Allinson took Boreham Wood to promotion in the Isthmian League Premier Division via the play-offs in the 2009–10 season, defeating Kingstonian 2–0 in the final.