In 2008, he played Second XI cricket for Surrey and Worcestershire before joining Northamptonshire until the end of the season. He made his debut for Northamptonshire against one of his former trialist clubs, Surrey on 8 September. At the start of the 2010 season, Harrison was a first team regular and kept wicket due to Niall O'Brien being on international duty and David Murphy still at University.
In 2008, he played Second XI cricket for Surrey and Worcestershire before joining Northamptonshire until the end of the year. He made his debut for Northamptonshire against one of his former trialist clubs, Surrey, on September 8th, 2010. At the start of the 2010 season, Harrison was a regular in the first team, keeping wicket due to Niall O'Brien being away on international duty and David Murphy still at university.