When Henry calls Libby to tell her Daphne has been out all day with a boy in a band (Ian), Libby says, "Lemme guess, he's a drummer?" In reality, Oliver James, who plays Ian, is a drummer. This could also be a reference to the movie 'The Reluctant Debutante' that this movie is based on. The character Ian is based on, David Parkson (John Saxon) is a drummer.
This film opened during war with Iraq which made Warner Bros. change the poster art for the film. Because the original artwork showed Amanda Bynes displaying a peace symbol, the artwork was changed so that the peace symbol was airbrushed out. The studio did not want anyone to think the artwork was a war protest.
The scene where Lady Dashwood is presenting Daphne Reynolds with a tiara for her coming out party was filmed after they had finished producing the movie. Amanda Bynes was in America and had already dyed her hair a dark brown. Eileen Atkins was in London.
Aside from shooting in London, they also filmed in Morocco and New York City. When Lord Dashwood withdrew his candidacy, he made that speech at the Old Royal Naval College where Cinderella and Sherlock Holmes were also filmed.
Before the US release of the film, print advertisements were altered to remove the peace sign that Bynes was giving in the poster. A rep for Warner Bros. explained '"In a time of war, we made a slight alteration so that we could avoid any potential political statement in a completely nonpolitical film."