Revealing mistake: When the firm takes more or less a full coach load to Liverpool, one shot from a bridge shows the coach with only 1 visible passenger and what looks like a different driver.
Factual error: The main plot of the film takes place between the draw for, and playing of, the FA Cup Third Round tie between Millwall and Chelsea. In reality the Third Round is drawn in early December and played in early January, however the film makes no reference to this time of year, ie. no signs of Christmas, in fact much of it appears to take place during summer time.
Continuity mistake: They are on the way to Liverpool, where they stop "Up North" and Zeberdee and Raff are kicked out by Bill to discover Liverpool fans nearby. The ruckus ensues and they get back on the coach. They then pull up at services. Surely at the Zeb and Raff scene, they must have been pretty close to Liverpool, but they still drive on and go to a service station that must have been (by the flow of events) slap bang in the centre of Liverpool.
Continuity mistake: Bill lets himself into Albert's house and shouts at him. The door is only half open when he does this, but when the shot shows the whole hallway and Bill walking down, the door is wide open.