The set used for Ross and Emily's wedding is the set that was used for Carol and Susan's wedding.
Although the bulk of the 2 part episode was actually shot in the Fountain Studios, in Wembley, London, it wasn't as well received in the UK as in the USA. Many British viewers regarded the episode as an ill-informed and patronising caricature of the UK and its people, causing the episode to be unofficially labeled "The One Where They Insult the English". As it so happened, the UK terrestrial TV channel "Channel Four", which had first-run terrestrial broadcast rights, had proposed a UK based episode to Warner Bros. TV.
The plane Rachel takes to fly to London is from Virgin Airlines. The guy selling the hats in London in the previous episode is Richard Branson, founder of the Virgin Group. Notice the Virgin Atlantic hats for sale on the cart.
According to the creators, many fans have asked if the character played by Hugh Laurie on the plane was Gregory House, from the show House (2004). The creators said it was a nice idea since the character shares similarities with the often grumpy and cynical Greg House, but the Gentleman on the Plane had a British accent (Hugh Laurie's actual accent), and Greg House is American. The creators have said that this rather significant difference gets missed because fans want to think that was really Greg House on the plane. It also ignores the fact that House did not debut for another six years afterwards.
June Whitfield, who plays The Housekeeper in this episode and Jennifer Saunders who plays Andrea Waltham were both a part of the show Absolutely Fabulous (1992). On the show they played mother and daughter, although in this episode they do not appear in the same scene.