Continuity mistake: When Carrie takes the first bite at her sandwich, she holds it perpendicular. Also, there's a bit of bread and egg standing out. A shot later, the bit is gone and the sandwich is parallel.
Revealing mistake: When the girls arrive at the wedding, a group of fans on the upper left corner are gathered watching the filming.
Visible crew/equipment: After the wedding, when Big and Carrie's car cross, a big, long rectangular black structure in the middle of the road is reflected on Big's car. Most surely where the camera and team were.
Continuity mistake: Steve confesses he's cheated Miranda and she walks to bed. His arms are positioned in front of him, then he moves them behind and tucks the pillows. From a brief opposite angle his arms are in front again. (00:33:46)
Continuity mistake: Sam places a piece of bread on the plate, but in the immediate shot her arm is raised and she's about to eat the bread. (00:34:26)
Continuity mistake: The bread lies perpendicular to the chopping board but a shot later it's parallel to it. (00:32:53)
Visible crew/equipment: During the Take or Toss scene, a rectangular black object is reflected on the champagne bottle, which is definitely not Carrie nor the closet. Most seemingly the filming camera. (00:31:44)
Continuity mistake: When Carrie places her blue shoes on the shelf of her brand new walking closet, her right hand lies near the shoes or several inches away, depending on the shot. (00:30:19)
Continuity mistake: While reading in bed, Big's right hand is either by Carrie's elbow or shoulder, depending on the shot. (00:21:59)
Continuity mistake: When Carrie reads the Beethoven poem her right fingers disappear from the book in the close-up shot.
Continuity mistake: During lunch, Miranda is pinching food in one shot but a split second later she is drinking from a glass without having grabbed it nor raised it. The scene takes place in real time. (00:12:00)
Continuity mistake: Carrie holds the Vivienne Westwood card with her right hand, but a shot later she holds it with both hands.
Continuity mistake: Miranda holds the fork with her right hand but a shot later it's in her left hand. (00:11:54)
Visible crew/equipment: When the girls greet each other, a filming light is reflected on the revolving door behind them. (00:07:49)
Revealing mistake: Carrie is flipping through her book's pages. In chapter 14 the lines "Upper East Side neighborhood" are repeated over and over again.
Visible crew/equipment: When Big is on the phone with Carrie while having trouble writing his vows, you can see a camera in the reflection in the window behind him.
Continuity mistake: When Big and Carrie are discussing the number of people invited to the wedding, Big says it's a circus and retreats to the bathroom to brush his teeth - at first, he has a toothbrush in his hand, but when he cuddles Carrie, the toothbrush is gone.
Suggested correction: It does show him placing the toothbrush down on the counter. You can see his eyes quickly look to the right and you can see his right arm slightly move a little as he places the toothbrush down on the counter just before he embraces Carrie.
Continuity mistake: Big is reading an email and points at the computer with his index finger extended. Shot cuts and now his palm is extended. (00:35:30)
Other mistake: In the "fashion show" that takes place as Carrie is packing, neither Miranda nor Samantha could even begin to fit into Carrie's clothes.
Character mistake: At the rehearsal dinner, when Steve walks up to Miranda she calls Steve "Dave." Dave is his real name.