Continuity mistake: When they go and visit Parliament, Ashley's hair is straight, but in the scene before and after, her hair is curly.
Continuity mistake: When they come and get the hostages for the hold up Riley is sitting at the end of the table with Chloe sitting in the middle. When Chloe leaves, Riley is shown sitting in her place.
Continuity mistake: Mary-Kate and Ashley go to London for the first time ever and have never seen the game 'Polo' before yet they are both experts on the game and can even win.
Continuity mistake: At the polo field Brian is holding his teacup in his left hand. In the next shot of him it's in his right hand and in the next shot of him it's back in his left hand.
Continuity mistake: The students see a London bus approaching and run across the road to get on it. The approaching bus is a red RML-class AEC Routemaster with a grey stripe. The bus they actually get on, seen from the other side, is a shorter RM-class Routemaster. This one has a cream stripe and a gold London Transport fleetname.