Trivia: The Christmas party was really filmed just before Christmas, with almost all of it filmed in the first take as everyone was in the holiday spirit already. Director Billy Wilder said "I wish it were always this easy. Today, I can just shout 'action' and stand back."
Trivia: To make the office appear larger than it was, the team used forced perspective - adult actors at the front, with child actors behind them, and tiny desks with wire-operated dolls at the back.
Trivia: The song sung by Baxter while cooking meatballs is "Capriccio Italien" by Tchaikovsky.