Though it wasn't in the original script, director Danny Boyle was so taken with the discovery of a recording studio by a railway track that he had the text altered to incorporate the trains and utilise the location as Gavin's studio.
During the scene where Jack first performs 'Yesterday', his friends claim that it's not as good as Coldplay. Ed Sheeran's role was originally meant for Chris Martin, the lead singer of Coldplay, but he couldn't do it due to scheduling conflicts, so then it was offered to Ed Sheeran. The joke was left in the script.
The flight attendant on Ed Sheeran's private jet is actually Ed's then fiancée now wife Cherry Seaborn
One early concept was that the colour purple was among the things that didn't exist, with a casual reference to the band Deep Purple now being called "Deep Orange." This idea was abandoned because it would be too much work to ensure no extras were wearing purple.
The main concert scene was filmed on the beach of the Norfolk Town of Gorleston, part of the Great Yarmouth Borough. Local residents were first to be chosen as the crowd extras filmed for the scenes.
When Jack flies back from L.A. to Liverpool, the camera lingers on the front of the airport building which reads "Liverpool International Airport". In reality, the sign on that building reads "Liverpool John Lennon Airport" but of course, that has changed in Jack's world.
According to director, Danny Boyle, some 20 Beatles songs were secured for use in the film, of which about 17 appear in the final cut. Expensive as it was to get the rights to the songs, it's still only the second most expensive "asset" he has acquired for a film, with insuring Leonardo Di Caprio's face taking the top seat.
In the movie Jack was hit on his bike and broke his front teeth and bloodied his lip. That actually happened to Paul McCartney in 1966. McCartney fell from his moped and chipped a front tooth in Liverpool. He also cut his lip and was left with a scar.
Some of the characters share their names with Beatles songs: Rocky, the roady/temporary manager, is named for "Rocky Raccoon", Ellie, Jack's love interest, is named for "Eleanor Rigby", which also happens to be the one song that Jack has trouble remembering, and Ellie's roommate, Lucy, is, of course, "Lucy in the Sky with Diamonds".
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.
Ed Sheeran, who plays himself in this movie, said in real life that the Beatles are his main inspiration for his songs.
The Beatles had zero input creatively, outside of approving of their music being used in the film. Danny Boyle stated in interviews that the film was "blessed" by McCartney and Starr, as well as the estates of Lennon and Harrison.
The original story for the movie was written by Jack Barth. It was much darker in tone, with the main character struggling as a musician in the new timeline and the premise of the alternate universe explored in more depth. When Richard Curtis did a rewrite, he made the tone much more lighthearted, put less emphasis on the premise of a new timeline without The Beatles and more focus on romance between Jack and Ellie.
Leading up to the dramatic event during the blackout, the unnerving music is actually the crescendo from "A Day in the Life". It is used again later on in the film.
In one scene, Debra compares Jack to Jesus, calling him "the Messiah". John Lennon famously stirred up controversy by claiming that The Beatles were "more popular than Jesus".
The font of the movie's titles resembles the original font which was used for the Beatles-Logo (with the exception of the bigger T that was used in the original logo). Also the poster shows Himesh Patel in a crosswalk, which is a reference to the famous cover of the "Abbey Road"-Album which shows the Beatles on the crosswalk at the Abbey Road Studios.
At one point Ed Sheeran suggests to sing "Hey Jude" as "Hey Dude". The Milwaukee-based Beatles-Metallica-crossover metal-band "Beatallica" actually did a parody version of "Hey Jude", entitled "Hey Dude". They officially released it in 2007 on their album "Sgt. Hetfield's Motorbreath Pub Band" (a parody to the Beatles-Album "Sgt. Pepper's Lonely Hearts Club Band"), which was full with other Beatles-covers in Metallica-Style.
Features a scene in the Birkenhead Tunnel, which has also been used as a location in Harry Potter and the Deathly Hallows Part1, Jack Ryan: Shadow Recruit, Fast & Furious 6 and Sky 1's bulletproof.
The second film directed by Danny Boyle to not be rated R in the United States. The first being Millions (2004).