Beginning as an apprentice at Sheffield United, Askham was released in May 2008, and had a trial at Manchester United in September of the same year. He signed for Chesterfield three months later on a one-month contract, which was extended to the end of the season in January 2009. He was sent out on loan to Garforth Town in March 2009, but returned to Chesterfield in May. He made his Chesterfield debut on 2 May 2009, coming on as a 70th-minute substitute for Scott Boden in a 2–0 home defeat by Bradford City. However, after just six months with the Spireites, he was released.