The One With Phoebe's Rats - S9-E12
Continuity mistake: At the party, when Monica and Rachel are talking about Gavin, Rachel has a napkin in her hand at one shot, the shot changes and the napkin is replaced by a drink. (00:13:20)
The One With Ross's Tan - S10-E3
Continuity mistake: In the scene where Joey and Rachel are sitting on the couch in their apartment after they decide their relationship is hopeless Rachel puts her head on Joey's shoulder. Her hair is on her face but when she lifts her head up in the very next shot her hair is now behind her right ear which she couldn't have done because her hands never left her lap. (00:22:00)
The One Where The Stripper Cries - S10-E11
Continuity mistake: When the girls and Mr Goodbody are talking about paying him the three hundred dollars, the top buttons of his shirt are ripped open. Half way though the scene this changes to only one button being open and his shirt looking neat and pressed, as if he had not started his strip yet. (00:13:25)
The One With Phoebe's Rats - S9-E12
Continuity mistake: Phoebe is sitting on her couch talking with Mike near the end of the episode. She puts the box with the rats on the coffee table and in the next shot, she is holding the box again. (00:18:35)
The One With Phoebe's Rats - S9-E12
Continuity mistake: At Rachel's birthday party, Phoebe reaches into the shoebox of rats, but straight away in the next shot, her hands are on the lid. (00:14:10)
The One with the Thumb - S1-E3
Continuity mistake: Monica's snort, Joey's knuckle cracking, and Phoebe's hair chewing are never seen in any other episode, before or after this one.
The One With Phoebe's Rats - S9-E12
Continuity mistake: In the series nine episode with the 'hot' nanny, at the end when Rachel is on the veranda/balcony thing with Gavin, before he says 'I do have feelings for you', the shot is over the shoulder and he has his hand on the wall of the balcony, when the shot switches to the front angle his hand is by his side. (00:20:55)
The One With Phoebe's Wedding - S10-E12
Continuity mistake: After Phoebe tells Monica that she is fired from being her wedding planner, Monica says that she has never been fired. However, in "The One With Five Steaks and an Eggplant" Monica gets fired for taking the kickbacks.
The One With Monica's Thunder - S7-E1
Continuity mistake: When Rachel and Ross go to talk to Monica about why she doesn't want to talk to her, Chandler's tie changes, from on the bed to on his lap.
The One With Ross's Tan - S10-E3
Continuity mistake: At the start, the lid on Joey's bottle is on and off depending on the shot. (00:00:20)
The One Where Monica Gets a Roommate - S1-E1
Continuity mistake: When Paul the Wine Guy first comes to Monica's apartment, Phoebe is standing in the kitchen telling Rachel that she just pulled out four eyelashes. But in the very next shot, you can see her sitting in an armchair in the living room. [Broadcast version only - in the extended DVD version there's a shot showing Phoebe walking to the chair.] (00:09:20)
The One With All The Kissing - S5-E2
Continuity mistake: A few days after the friends have returned to New York following Ross' wedding, Monica's hair is suddenly about three inches longer and a completely different style than it was in London. It was previously just above her shoulders in a sleek "pageboy" style. Once back home, it is much bushier and longer, well over her shoulders. This was obviously due to Courtney Cox growing her hair during the break in-between Season 4, which ended with the Ross/Emily wedding debacle, and Season 5. (The first episode of Season 5 was filmed the previous season and was Part 2 of Ross and Emily's wedding).
The One Where Ross Got High - S6-E9
Continuity mistake: When Rachel tells Phoebe that she's making a traditional English trifle, Monica's holding a cloth napkin, but in the next shot the napkin's suddenly gone and she's now holding forks.
The One Where Ross Got High - S6-E9
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)
The One With Phoebe's Dad - S2-E9
Continuity mistake: When Ross gives the super the money and asks "will this help with the knob" the super says that the place isn't open until Tuesday. When he says that the money is in his right hand. Then when he asks "am I not saying it right", the money in his right hand is gone.
The One With The Home Study - S10-E7
Continuity mistake: When Mike says "I am going to make this decision for us. What do you think we should do?" he is holding the check. The very next shot shows the charity worker taking the check off the desk and giving it back even though Mike never put it down. (00:20:35)
The One with the Sonogram at the End - S1-E2
Continuity mistake: Toward the end of the episode, the exterior shot of Central Perk shows about 8-10 people inside the cafe, at the coffee bar, at the tables. But the next interior shot shows the cafe is empty except for our six Friends, lounging in the closed cafe while Rachel cleans up. (00:12:15)
The One In Barbados, part 2 - S9-E24
Continuity mistake: In the scene where David wants to propose, when Phoebe and David get seated in the restaurant Phoebe puts her bag on the floor to the left of her chair. When there is a wider shot again, it has vanished. (00:25:25)
The One With the Sharks - S9-E4
Continuity mistake: When Ross explains to Phoebe about "Vikram" the big dark jewel on her necklace switches repeatedly from hanging at the left side of her neck to the middle, then to the right side and again to the left side again between shots. (00:16:10)
The One With Ross's Inappropriate Song - S9-E7
Continuity mistake: When Ross is holding Emma, the position he is holding her changes.