Continuity mistake: When Monica comes into Phoebe's apartment for her Surprise Bridal Shower, the view of the hallway outside the apartment is a dead end on the right side (the left side cannot be seen), however, in S7:E12 (The One Where They're Up All Night), both when Phoebe is disposing of the fire alarm and when the fireman is at the door, it is clear that there is another apartment opposite hers, as well as a trash chute on the right side. (00:18:25)
Continuity mistake: When Phoebe finishes telling Rachel about her thanksgiving dream about Jack, Chandler is looking straight ahead with his arms crossed. Cut to the next shot when Jack and Judy are coming out of Monica and Chandler's room, and his arms are immediately uncrossed and he's looking at the women. (00:20:05)
Continuity mistake: 12 hours before the wedding, Monica asks Joey to speed it up. Here she is stirring a bowl. In the next few seconds you can see Monica holding some condiments in her hand. After Phoebe answers, Monica is stirring again and the condiments are nowhere to be seen.
Continuity mistake: When Ross first tries to flirt with the pizza girl he has money in his hand. When Chandler walks over he gives his own money for the pizza, she leaves, and Ross still has his money. In the next shot when he shuts the door, his hands are empty, then it is back in the next shot when Ross yells at Chandler.AttitudeEra1
Continuity mistake: Rachel is telling Chandler to break off his relationship with Joanna, who had walked through the room and went into Chandler's bedroom, shutting the door. By the end of the conversation between Chandler and Rachel, the door is open but no one has entered or left the room.MovieFan612
Continuity mistake: When Rachel and Phoebe are in Central Perk talking about the Princess Leia Fantasy, a guy in a yellow shirt and white pants is standing at the bar behind Phoebe. As they talk he walks to the door and leaves, but in the next shot he is standing behind Phoebe again, just as she says "That's the moment when she becomes a woman." (00:08:10)Babatomyfriends
Continuity mistake: At the beginning when Rachel and Monica talk about the free coffee sample, Rachel puts it down on the counter to her right. In the next shot it's lying to her left with no time to have gotten there. After that it switches from the right to the left and back again. (00:01:25)Babatomyfriends
Continuity mistake: In the scene where Phoebe tells the gang about her "Relaxitaxi" idea the position of Chandler's left arm changes between shots. In the frontal shots it's lying the back of the chair and in the shots from behind it's wrapped around Monica's shoulder.Tanngrisnir
Continuity mistake: In the beginning of the episode when Joey tells Chandler that he hasn't forgiven him for kissing one of his sisters, Monica and Chandler's TV, entertainment set and ferns are missing from the set and there are cables protruding from the wall. The area is completely bare except for the French poster. Everything's back to normal slightly later in the episode.
Continuity mistake: Just after the opening titles cut to Central Perk, four people can be seen having a conversation through the window. In the next shot, there is one person sitting next to the window and a waitress has appeared out of nowhere. (00:03:05)Casual Person
Continuity mistake: When Phoebe enters the coffee house to get Joey's advice on her outfit for Mike's sister's party, it cuts to Joey saying "You look stop-eating hot", and Phoebe's left hand can be seen making a nervous up-down motion in response. But when it cuts back to her, it is her right hand making the motion and her purse is now in her left hand.NatalieNinetales
Continuity mistake: In the opening scene in Central Perk when Paul (Elizabeth's dad) takes Ross to one side to talk to him you can see the girl in the blue top enters the door twice: first the shot after Paul says "I'm funny like that" and then again after Ross says "I realise it upsets you".