Tatum became British Champion twice; in 1987 and 1990. In 1990 Tatum was the highest placed British rider in the World Final at the Odsal Stadium in Bradford, finishing in 7th place with 9 points from his 5 rides. In the 1990 World Final qualifying rounds, Tatum had won the Commonwealth Final at the Belle Vue Stadium in Manchester. It was his third Commonwealth Final win after having done so in 1987 and 1988. Tatum would add a fourth Commonwealth crown to his trophy cabinet in 1992.