Continuity mistake: When Miranda takes a sip of her latte in the restaurant scene with Steve, only half of her upper lip has foam on it. In the next shot of her it is covering the whole of her upper lip. The same happens to the foam on Steve's lip when he mimics her. (00:24:50)
Continuity mistake: When Carrie is feeling depressed in Mexico and is being fed food in bed by Samantha, there is a tea pot on the tray on the bed. The scene changes back and forth between Samantha and Carrie and each time it changes, the style of the tea pot completely changes. When it's a shot of Samantha, it's a regular tea pot with a lid, and when it's a shot of Carrie, it changes to an art deco style pot with no lid whatsoever.
Plot hole: While the wedding party is getting ready to leave Charlotte's apartment, Big calls Carrie's cell phone. Lily (Charlotte's young daughter) answers, immediately closes it without speaking, then drops the phone into her purse that she takes with her to the wedding. Big continually calls back, but even though Lily is always with one of her parents, no can hear Carrie's phone is ringing inside Lily's purse. Lily only closed the phone, it was not turned off, the ringer was turned up, and the battery was charged. Lily and Harry rode to the library separately and during the time Big had been trying to call Carrie. Harry should have heard the phone.
Continuity mistake: In the scene where Carrie and Big are in bed (Carrie is reading the Love Letters) the library card Carrie uses as a bookmark keeps changing position. She opens the book and holds the card behind the book cover, then when you see a close-up of the text you can see the card is being held inside the book. Then it's back behind the book cover. (00:22:25)
Other mistake: In the scene where Carrie is reading bits of love letters to Big, she reads from a letter from Napoleon to Josephine and uses the line "I awake consumed with you". In Napoleon's actual letter he wrote "I awake filled with you" and for a brief moment you see the book Carrie is reading from, which shows the correct text. (00:22:05)
Continuity mistake: When the girls are at the restaurant in Mexico and the waiter brings over the drinks, he first hands Charlotte the bottled water and then hands Samantha the drink. The camera pans back to the waiter holding the drinks and the bottle of water is still there along with 2 other drinks.
Continuity mistake: When Samantha is lying on the table covered in sushi and the phone rings, she moves and the piece of sushi on her shoulder falls down. There is a visible piece of double sided stick tape there to hold the sushi in place. In the scene time elapses, but it is understood Samantha never leaves the table and remains covered in sushi. When the shot returns to her close up, the piece of tape has been removed from her shoulder.
Visible crew/equipment: Early into the film, the girls walk on the street next to a white window shop. The reflection of the opposite sidewalk is that of a wooden barrier with hundreds of people (fans? Crew members?) behind; but when the angle changes, the barrier is gone and the sidewalk is filled with passers by. (00:07:35)
Continuity mistake: When Charlotte, Anthony and Carrie are planning the wedding, Carrie has a pen attached to her dress strap which keeps changing positions (it doesn't disappear, we can still see its black cap) while she is sitting on the bed and when she gets her wedding dress out of the closet. (00:16:00)
Continuity mistake: In the extended scenes of the movie when the four girls are trying on Carrie's clothes from the eighties, they are sitting on the bed together watching Lily coming out of the bathroom draped in numerous handbags. They have all changed back into their normal clothes, but when Lily continues to walk closer to the girls, the angle changes and the four girls are back in Carrie's outfits again, dancing around in the bedroom.
Plot hole: In the scene where Louise gives Carrie her new phone, she tells Carrie of her new phone number and Carrie gets upset because she has lost her old 917 prefix; but all Carrie did was throw her phone away into the ocean, she didn't have to change her number. I'm sure, as here, in New York people lose or break their phones constantly. It's just a chance to explain why Big hasn't got her number - her new number - so he couldn't call her and apologise (but what about her home phone number; that wouldn't have changed - Big would know that number, surely).