Continuity mistake: When Carrie is telling Alex about her Parisian fans and the party she's been invited to, her cigarette pack not only changes position in her hand with her coffee cup, but also disappears and reappears several times.
Continuity mistake: When Carrie has left the dessert place and is walking in the street; just before she sees the small child, there are two extras (male and female) behind her using a single umbrella. After the small child hits Carrie on the head, you can see the same two extras behind her without an umbrella. When the small child sticks out her tongue at Carrie, you can again see the two extras right behind Carrie, still not using an umbrella. When Carrie looks back again, just before stepping in dog poo, suddenly the two extras are completely gone, and the street is almost empty. Then when Carrie does step in the dog poo, the two extras are seen again farther back, again using the umbrella. In the next shot, a close-up of Carrie, the two extras are right behind her again, and passing her, without using an umbrella. At this point Carrie speaks to an older man coming from in front of her, and the two extras have completely disappeared from the street again, even though they have just passed her. This entire sequence took place in a very short period of time, and was obviously edited together.
Continuity mistake: When Miranda is running in the streets looking for Mary, there is a close-up shot of her face. You can see that it's raining heavily, as the rain is apparent in the scene. But during the rest of that sequence, as she is out in the streets, there are no other signs of rain, or of people being affected by rain. There is just snow on the ground.
Continuity mistake: In the first shot of the diner as the girls are waiting for Carrie to arrive, the baby photo of Charlotte's daughter is not visible on the table. When Carrie comes in, there is a clear shot of the entire table, and the baby photo is still nowhere in sight. But in the shot where Carrie sits down at the table with the girls, the baby photo is suddenly sitting upright on the table near Charlotte, and fully visible. There was no time for this to happen, as they are just sitting down. Carrie is still hugging her friends (Charlotte) at the table.