Jennifer Saunders had laryngitis while filming which can be heard in her voice.
Edina runs into Christian Lacroix and says she's not wearing any of his designs (although her cross necklace probably is by Lacroix). However, when she later runs into Stella McCartney she is wearing a Chloe t-shirt designed by McCartney.
The gag about Lady Candida De Denison-Bender being unable to take her dog with her to Paris was added because Tilly Blackwood was unavailable for the location shooting.