The Averard Hotel, in the Lancaster Gate area of London, was the hotel used (both interior and exterior) as "The Claremont". The Averard was originally built as a townhouse by a wealthy doctor before 1910. In 1925, the townhouse was reconfigured as a hotel, and has most recently been a family-run bed and breakfast. The hotel discontinued operations (as a hotel) in 2009 and the building was converted to non-hotel residential use.
Beaulieu Palace House, where some scenes in this movie were filmed, is an owner-occupied ancient palace, dating to the fourteenth century, with parts of the house and gardens open daily to the public. It is a member of the Treasure Houses of England consortium, and the National Motor Museum, founded by Lord Montagu of Beaulieu, occupies a separate building on the estate. Lord and Lady Montague and their son, Jonathan Douglas-Scott-Montagu, received an on-screen "special thanks" credit.
The song sung by Georgina Hale in this movie: "It's Never Too Late To Fall In Love" was also sung by Hale and Max Adrian in Ken Russell's The Boy Friend (1971).
Celia Johnson was Mrs. Palfrey in the original movie. She was also the lead actress in the Brief Encounter movie mentioned in this movie. Had to be an inside joke to those who knew this information.