Windfall is a 1955 British comedy film written by John Gilling and directed by Henry Cass, starring Lionel Jeffries, Jack Watling and Gordon Jackson. Dad's Army star Arthur Lowe also makes a brief appearance in the film.The film was also released as Dangerous Money.
The lives of shop assistant Arthur Lee and his family are transformed when he finds £2,000 on top of a bus. Arthur's daughter's dodgy boy friend steals the money, but lands in trouble when it's discovered to be counterfeit. Things turn out well for Arthur when the resulting publicity gives a boost to his business.