When Eddie says, "Money may be your god, but it ain't mine," this is almost exactly what the real life lookout for the bank robbers said over his walkie-talkie during the robbery. This is known because, as in the movie, a ham radio operator tape recorded some of the conversations broadcast by the robbers.
Roger Donaldson said one of the most difficult days of filming was when he filmed the brothel scene. The scene called for the women to be walking around wearing only garters. However, Donaldson said that when he went to film the scene he discovered that most of the women shaved their pubic area, , which would have been anachronistic for 1971. So the actresses had to wear pubic wigs called "merkins." This caused a problem because the merkins were hard to secure in place and kept slipping, causing Donaldson much aggravation.
Scotland Yard considered charging the ham radio operator, who recorded the walkie-talkie conversations between the bank robbers, with illegally listening to their transmissions, but no such charge was filed. Lloyds Bank, however, paid him a reward of £2,500.
Aldwych station was chosen to film the underground scenes because the true Tottenham Court Road station had been modified extensively in the early 1980s. Only Edgware Road still has any resemblance to its original look.
Based on a real heist where thieves tunneled underneath and up into the vault of a Lloyds Bank branch in London. Featured in The Baker Street Bank Burglary (2023) "History's Greatest Heists".