Continuity mistake: When Frank sees what he thinks is the Ghost of Christmas Future in the elevator, he flips out and accidentally clocks Grace in the jaw. She puts her right hand to her face, but in the next shot she's holding her left hand up.
Continuity mistake: The strings of lights for the reindeer reins change continuously from one strand to two.
Continuity mistake: In the scene when Jamie Lee Curtis brings Dan Aykroyd home, you can visibly see she is wearing pantyhose. However, just a few second later, inside the apartment, she takes off her dress and is only wearing panties. (00:58:40)
Continuity mistake: After Perry and Harry leave the lake with the girl in the trunk, the headrests are missing from the front seats, but when the shot cuts to them arriving at Harry's hotel, they reappear.
Continuity mistake: When Scrooge walks into the Cratchit home at the end, there is a "Home Sweet Home" plaque on the wall. The shot then cuts away from it. The next time the plaque is visible, its lettering has changed.
Continuity mistake: When Minty arrives at the North Pole in a balloon, she passes Santa's house twice.
Continuity mistake: When the guy and girl are sitting in the car, they put the newspaper with duct tape up on the window but later on both the duct tape and newspaper are gone.
Continuity mistake: Near the end, Mike is hanging the glass angel he got from Artie on the tree. Nina comes in through the front door, leaving the door chain hanging (unlatched), yet, in the very next shot the chain is on.
Continuity mistake: When the reindeer gets into the house and runs around, it knocks over a TV set. All of the magazines that are on top of the set come crashing to the ground, including a TV Guide with "Get Ready For A Fabulous February" (or something like that) in big letters on the cover. Interesting since the movie is set around Christmas time.
Continuity mistake: When Fred gets to the North Pole and the Security elves take him down. Fred comes up and the snow on his face change between shots.
Continuity mistake: When Dr. Sawyer is giving Kris the exam, during the part where Kris is doing the physical coordination test, we see Kris from Sawyer's point of view, and Sawyer is drumming his fingers. When the shot switches to Kris's, he is fingering his eyebrow. When it switches back, fingers drumming. Finally, when it switches back again, his hands are neatly folded in front of him.
Continuity mistake: The scavenger discussing Scrooge's bed curtains with the housekeeper lays the curtains down in his lap, then the next shot he is holding them up again.
Continuity mistake: When Frosty gets off the train because Karen gets sick, from the magician's view it appears the train is slowing down and is very close to Frosty, but when the shot goes back to the magician, the train appears to be going much faster and is much further away.
Continuity mistake: When the Winter Warlock's icy heart melts, he is holding a toy locomotive with its front showing, but the next shot shows the locomotive's rear showing.
Continuity mistake: In court, the camera shows Susan to judge her reaction to the lawyer talking, and she is sitting upright in her seat. It then changes to Dori, who is sitting right next to Susan. If you look in the bottom left hand corner however, you'll see that Susan is no longer sitting upright, and is instead leaning on Dori. There would be no time however for Susan to lean on her mother in the time the camera takes to move to another shot.
Continuity mistake: In the scene when Justin's father is coming out of the shed dressed as Santa Claus (the second time), the clock next to Justin reads 12:00. When he hears the "Ho Ho Ho" and gets up out of bed to go to his window, the clock says 11:56. (01:15:40)
Continuity mistake: When Cratchett gets the bird from the shop, it's clear that the bird is a duck. But throughout the entire film he's referred to as a goose.
Continuity mistake: In the scene where Ben Affleck gets hit in the head by the shovel in the beginning, when the shovel is about to hit him, the paper is not on fire for a split second. Then when he's on the ground it's on fire again.
Continuity mistake: When Steve Finch crosses the street to talk to Buddy Hall outside the hardware store, he raises his collar around his neck. Slightly further on in the scene, when the two are in front of the tree, he places his hands in his pockets. The two then walk back to Hall's pickup, at which point Finch's collar is down, and returns to being up when they finish walking. At no time does Finch remove his hands from his pockets.
Continuity mistake: When Kermit is in the park looking at his plaque he wipes off all the snow and reads it. In the next shot of him walking to a nearby bench the plaque is covered again but it is not snowing heavily enough to have been covered so fast.