Tim's professional acting debut was in 1968, in the West End production of Hair. The West End is the UK's version of Broadway.

In 1973, Tim starred in The Rocky Horror Picture Show as Dr. Frank-N-Furter in the West End. In 1975, the movie version of The Rocky Horror Picture Show was made, and Tim, once again, played Dr. Frank-N-Furter. Richard O'Brein, the creator and writer of RHPS, credits Tim as the inventor of Dr Frank-N-Furter as we know him, based on his West End performances. Originally, Dr Frank-N-Furter was going to be bleach-blonde, with a German accent and more of a B-rate horror mad-scientist outfit. Tim created the iconic Dr Frank-N-Furter everyone knows.

Tim has over 240 acting credits to his name, not counting ones where he plays himself (cameos).

In 2012, Tim suffered a massive stroke that required brain surgery. After that, he suffered from a lot of health problems, and he declined over the years, until he finally died.