Scott Calvin AKA Santa Claus (Tim Allen) has his hands full with Christmas deliveries looming, wife AKA Mrs. Claus (Elizabeth Mitchell) expecting a baby, nosy in-laws (Ann-Margret and Alan Arkin) visiting and Jack Frost (Martin Short) trying to take over his job. He must pretend his North Pole workshop is really somewhere in Canada to dupe the in-laws, and deal with sabotage by an insanely jealous Jack Frost and the additional stress of his ex-wife and her husband (Wendy Crewson, Judge Reinhold) visiting as well. Juggling family issues and the interference by Frost makes Santa/Scott reach his limit and he accidentally invokes the escape clause in the title by holding a magic snow globe and wishing he’d never become Santa. His wish is granted and he goes back in time and does not like what he sees. Meanwhile, Jack Frost does take over and commercializes and cheapens everything about Santa’s former job. Scott/Santa has to decide whether to try to resume his Santa role and go back to how things are, or even figure out if this is possible.