Mills was assistant at Fulwell Golf Club from 1948 and was tied for third place at his home course in the southern section qualifying for the 1949 Daily Mail Tournament, after a first round of 67.

[5][6] Mills never won the Gor-Ray Cup, the assistant professionals' championship, but was runner-up to Geoffrey Hunt in 1954.

[9] In 1956 he was joint-second, a distant 9 shots behind the winner, in the Daks Tournament at Wentworth, and he reached the semi-finals of the News of the World Match Play, losing 6&4 to Harry Weetman.

In 1957 selection for the team of 10 was based on a points system over a two-year period ending after the 1957 Open Championship.

In the 1957 match, Mills was not selected for the foursomes but played Jack Burke Jr., the American captain, in the singles.

[21] In early 1961, Mills left his position as the professional at Pinner Hill to become a full-time tournament player.

[23] After a loss of form caused by his back problems he attempted a return to tournament golf in 1964, but this also proved unsuccessful.