During the 1970s Mills appeared as the fraudulent medium Mr Tyson in The Treasure of Abbot Thomas (1974), as chip shop proprietor Len Holmes, in The Sweeney episode "May" (1976)[2] and as paedophile Reginald Barton in the Granada Television daytime series, Crown Court, the episode entitled "Common Sense" (1978).

[3][4] Also in 1984 he appeared as Harry Martin, an accountant or book keeper, employed by agoraphobic bookmaker Albert Wendle in the Minder episode Get Daley!

[5] He again appeared in Minder in 1991, this time in the episode The Greatest Show in Willesden in which he played Arthur Daley's barber, Len.

In 1997 he played Albert Potter in the Yorkshire Television period drama Heartbeat, the episode entitled "Small Beer."

[1][8] He starred alongside Ray Brooks in the 1984 hit BBC drama Big Deal as the grumpy bookmaker Gil.