- Approval of God: The surviving Beatles (Paul and Ringo) and the widows of the deceased members (Yoko Ono and Olivia Harrison) were made aware of the film prior to production and the premise met with their approval.
- Deleted Role: Ana de Armas played a role as a rival Love Interest that was deleted from the final film, but can be glimpsed in some trailers. This was apparently because test audiences found Jack too unsympathetic.
- Dueling Works: With Blinded by the Light - another British film that's a love letter to 60s/70s music (in this case Bruce Springsteen).
- Fake Brit: Downplayed. Glaswegian actor Robert Carlyle cameos as an alternate universe version of Liverpudlian John Lennon.
- Fake Nationality: Downplayed. Sarah Lancashire is a Lancashire native putting on a Liverpool accent as Liz.
- Missing Trailer Scene: The trailer has an additional sequence from Jack's Late Late Show interview in which James Corden, wanting a demonstration of Jack's songwriting skills, challenges him to "write something" on the spot. Cut to Jack performing "Something" from Abbey Road. The scene is also notable for featuring Ana de Armas in her Deleted Role.
- Orphaned Reference: There's a comparison made to Coldplay's "Fix You" being the greatest song ever made by one of Jack's friends. This was less random when Chris Martin was meant to have a role in the film.
- Real-Life Relative: The flight attendant on Ed Sheeran's private jet is actually Ed's fiancee Cherry Seaborn.
- Throw It In!: Danny Boyle heard about a recording studio beside a railway track, and had Gavin's become one in order to incorporate it.
- Uncredited Role: Robert Carlyle as John Lennon.
- What Could Have Been:
- Ed Sheeran's role was originally meant for Chris Martin.
- In the first draft of the script, Jack only become moderately successful thanks to the songs. This was changed to him becoming a worldwide sensation, and his love story with Ellie being emphasised too. Overall the story became Lighter and Softer.
- There was going to be a scene where Jack encountered George and Ringo in a pub. However, Boyle and Curtis decided that this would dilute the impact of Jack's meeting with John Lennon.
- Curtis toyed with the idea of having the color purple not exist in the alternate reality but quickly abandoned the concept because it would have required far too much attention to detail (i.e. sets, costumes, etc.). The band Deep Purple would have been called "Deep Orange".
- Working Title: Cover Version, All You Need and Jack Got Hit by a Bus.
Trivia / Yesterday (2019)