The soundtrack erroneously credits three songs to Sam Bell, who played George. In the movie, "Hello Little Girl" was performed by Aaron Johnson (John); while "Twenty Flight Rock" and "Love Me Tender" were performed by Thomas Brodie-Sangster (Paul). Two other songs performed by John, and a duet by John & Paul, are correctly credited to Johnson & Sangster; while George is only seen singing together with Paul & John in the final track performed by the Nowhere Boys.
When John leaves Julia's house he's wearing an open-necked shirt. When walking along through the park he's wearing a tie, arriving at Mimi's gate he's tieless again.
When offering a cheek to kiss on John and Julia's first outing she offers her left cheek when the camera is behind John but when the camera switches to a side view she is offering her right.
After John buys the 45rpm of I Put a Spell On You, he meets up with Marie and tosses the record to his mate and goes off with Marie, ending up at one or the other's flat, where they then play the record he had just given to his mate.
When Paul first saw John, John was singing "Come and go with me" not "Maggie Mae"
In the scene after the trip to Blackpool Julia Lennon says that they have spent the day on the South Pier, when in fact the pier featured is the North Pier.
During the funeral of John's mother, Paul plays the guitar, and an angry John physically attacks him. The real Paul McCartney stated that he and John never had an altercation of any kind.
John Lennon punches Paul McCartney in fact Paul McCartney stated John Lennon never punched him.
At their first gig after the founding of the band, John and his friends already performed a "The Quarrymen". However before that they were called "The Blackjacks", a name that was not mentioned in the movie. That however could be a hint to the fact that the band quickly changed their name to "Quarrymen".
In the scene where John is playing "Hello Little Girl", just after the car accident, when he finishes the song he turns off a tape recorder which has presumably been recording the song. The tape is right at the beginning of the reel - not enough tape has been used to record the song.
The cigarettes smoked seem rather 'king sized' for the era, when Players and Woodbine were prevalent.
A Pono ukulele is shown in the music shop, a brand that didn't exist until the 1980s.
When John is bicycling through the park "Wild One" by Jerry Lee Lewis is heard, a song that was not released until 1958. The scene takes places in 1955.
Although George Smith's grave says he died in June 1955, he is seen listening to the Hancock's Half Hour episode The Diary, which was first broadcast Dec 30 1956.
In the headmaster's office scene, the boys have apparently been reading Parade magazine. Before 1960 Parade was titled Blighty Parade.