Sir Anthony Hopkins, as a guest on Inside the Actors Studio (1994), said that he got tips on how to play a butler from real-life butler Cyril Dickman, who served for fifty years at Buckingham Palace. Dickman said "There's nothing to being a butler, really; when you're in the room, it should be even more empty."
None of the filmmakers had any experience with the way a great English country house is run nor the minutiae of a butler's life. Kazuo Ishiguro was the first to admit this and had to learn about it in the course of writing his novel. Sir Anthony Hopkins was afraid of making all kinds of gaffes and requested that an experienced butler somehow be attached to the unit. This was done, the advisor being Cyril Dickman, the retired Steward to Queen Elizabeth II, and he, in time, brought in others who were experienced in the exact way of doing things in a big house like Darlington Hall. There was an exact pecking order, with specific servants to handle specific assignments. From the butler and the housekeeper on down, there were under-butlers, footmen, housemaids, under-housemaids, the cook, the scullery boys, the gardeners, grooms, and gamekeepers, even the servants of the servants.
The part of Miss Kenton (Dame Emma Thompson) is one of only three movie roles for which Meryl Streep has ever been turned down.
Jack Lewis (Christopher Reeve) is a composite of two different people. In Kazuo Ishiguro's source novel, the new employer of James Stevens (Sir Anthony Hopkins) is an American by the name of Farraday and has nothing to do with Mr. Jack Lewis, the Senator.