James Harris was an early developer as a cricketer. An energetic seamer and useful lower-order batsman, he was the youngest person to appear for Glamorgan 2nd XI when he turned out in 2005 at the age of 14 years and 353 days, and a month later he was the youngest to appear for Wales Minor Counties, taking 3 for 48 against Netherlands. In 2006 he signed a contract with Glamorgan despite being just 15, and in the same year captained England Under-16s. He made his debut aged just 16 and a few weeks later became the first 17-year-old to take a seven wicket haul in the Championship. He was rewarded for his promising debut season with a trip to India in late 2007 as part of the England Performance Programme squad, and was part of the England squad for the Under-19 World Cup in 2008..