Continuity mistake: When Lara Jean and Peter are creating the contract, the writing for the "Ski Trip" changes between when Peter writes it and when they sign the contract.
Factual error: In the second-to-last scene, Rachel is leaving Singapore for New York. Nick goes onboard to propose and convinces her to stay in Singapore for one more night. However, this is not possible in Singapore due to strict laws which state that those who enter the departure area must have a boarding pass and intend to leave the country. Those who have a boarding pass but no intention to depart will be prosecuted. In 2018, 40 people were arrested for various offenses, such as sending a friend off or meeting their idols.
Suggested correction: Nick's family is extremely rich, powerful and famous in Singapore. That might have been enough to get him special treatment or an exception to the rule.
Continuity mistake: When Ana and Christian are having sex on the dining room table, she drops Christian's pants below his butt. Scene cuts and Christian's back is shown, with his pants above his butt. Then cuts back and they're below again. (00:54:40 - 00:56:50)
Other mistake: When Kate is taking the Medical-Surgical Nursing Exam, there are 2 separate #23 questions at the bottom of the page. (01:09:30)
Continuity mistake: When Buster is shot, his hat with the hole in it disappears.
Continuity mistake: Juliet is on the bed with little girl Kit. The child has a ribbon is her hair then looks up at Juliet and it becomes a slide. Next cut it is a ribbon, then a slide. Then the girl sleeps on Juliet with just a ribbon visible. (01:19:00 - 01:20:00)
Factual error: Simon receives an email notification at the dinner table from Blue on his cell phone. The cell phone screen indicates that the time is 3:20, which is inaccurate for a mealtime because it is already dark outside and crickets are chirping when he excuses himself to go outside to get some air. (00:28:10)
Continuity mistake: When Rick and Kirsten are at the game, just after they shout at one of the players, Kirsten drinks from her cup, but in the next shot, the cup is suddenly back in the armrest holster. (00:33:40)
Continuity mistake: Danica gets to work at the beginning of the movie, and her coworker passes her a folder. The folder keeps moving from under her arm to her hand, back and forth between shots. (00:03:00)
Continuity mistake: When Willy is in bed looking at photos with the camera behind his ear, his cup of coffee is directly in front of his hands. A moment later when the camera shifts to in front of him, his coffee is way off to his side, nowhere near his line of sight. (01:00:12)
Continuity mistake: When Lucas exits the bar, the Toyota truck appears to be parked close to the porch, but there's a lot more space between them during and after the fight. (00:17:39 - 00:18:46)
Continuity mistake: In Alice's apartment the clock on the wall has the time as 8:40 when she is standing and kissing David. They have sex and Veronica comes over. Alice and Veronica talk and the clock still shows 8:40. (01:20:00)
Continuity mistake: After performing 'surgery' on the bear, Tasha goes visit another one of her little patients. Before she sets foot in the room bickering with Jeff you can see her hair flows left and right of her colourful pin on the coat. Inside the room, her hair is just on one side, switches side, and it stays that way till she exits the room, when once more there is a visible change at the cut. (00:03:30)
Visible crew/equipment: When Zoe walks into Anderson's office and tells him she's meeting Maya at the apartment, just as Zoe says, "Uh oh," there's a visible blue T-mark taped to the floor. (00:49:05)
Continuity mistake: Abby's annoying boss puts her friend to work giving him a box to carry to his car. In a rather blatant continuity mistake, the penguin is facing opposite directions between shots. (00:03:15)
Continuity mistake: Kevin and his daughter handed the invite for the dream-like contest to the protagonist. He shoos her away saying "Liv, don't you need some milk with that cookie?" His arms are crossed behind his back. Next shot and she is walking away from him with his hands crossed in front of his crotch. (00:02:20)
Continuity mistake: When the tour guide says "There are two possibilities", Kurt and Elisabeth are holding hands. The camera then cuts to a closer shot of Kurt where he and Elisabeth are no longer holding hands, before then holding hands again. (00:02:05)
Continuity mistake: Violet's mom is hot combing her hair at 5 AM; as she performs this operation on the left side, the right side has straight black hair all in front of the shoulder. When Violet tells her that dad is coming, she moves to the right side. Sanaa Lathan's hair now is suddenly all behind the shoulder. (00:05:20)