Phase Three was originally intended to be a short film but was extended to feature length midway through production.
During filming of one scene, a drunken cyclist stopped by as he was adamant that Steve Tuck was in fact a famous rapper from Holbeck, Leeds.
The film was in production for over a year due to director James McEvoy being involved in other projects at the same time.
The entire film's sound was recorded in post-production by Tom Wilkin as no microphone was used on-set. All dialogue in the film was also recorded in lengthy ADR sessions.