Miscellaneous: The newspaper clipping handed to Edie lists Billy's name as "Tommy Quinn."
Continuity: When Andy is on the phone with Brigid and he is looking at Edie's picture, we can see that his thumb nail is broken. But the next second, in the same scene, his nail is fine!
Revealing mistakes: When Edie reads the paper about Billy's wedding, try to freeze the scene. If you read what the paper actually says, you will find out that, except for the first few lines that talk about the wedding, it also talks about some nonsense stuff that is copied and pasted all over the paper!
Anachronisms: Andy Warhol and Edie attend the New York City premiere of Darling (1965) (which opened in that city in August 1965) a month after Andy is seen watching "I Dream of Jeannie" (1965) on TV), which didn't premiere on television until mid September 1965.
Anachronisms: Throughout the film, Edie's cigarette packages are period-correct Viceroy packs, but the actual cigarettes she is seen smoking are Marlboro Lights, which did not become available until 1972.
Anachronisms: Campbell's tomato soup cans in Andy Warhol's kitchen cupboard have more modern label featuring upper and lower case typography, not the ones with all capital letters in use during Sixties.
Factual errors: In reality, on the photo that shows Warhol and Edie in front of the New Yorker skyline, he does not wear shades.