Howarth was offered a full contract in 1973 and achieved the highest score (159) by any Surrey player that season.

In 1985, he continued as a non playing captain as Surrey used Tony Gray and Sylvester Clarke as their overseas players that season.

Howarth described this as a "...frustrating experience... and was disappointed not to have the opportunity to prove my qualities as a captain at Surrey..."[5] Howarth played some Test cricket with his elder brother Hedley, but most of his 47-Test career did not overlap with Hedley's.

His partnership with Jeff Crowe of 210 runs was impressive given the New Zealand total of 283.

His contract with New Zealand Cricket was terminated in 1995 with a clause preventing him from "going public" for three years.

[12] Howarth was appointed a Member of the Order of the British Empire, for services to cricket, in the 1981 Queen's Birthday Honours.

[13] In the 1984 Queen's Birthday Honours, he was promoted to Officer of the Order of the British Empire, also for services to cricket.