The "Hotel Argento" where the Collector has his victims is a nod to the cult Italian horror director Dario Argento.
The mannequins are a nod to the film "Maniac" (1980).
A sequel titled 'The Collected' was announced to be in development in May 2019. In October that year, production was mysteriously halted after only eight days of shoot and never progressed. As a result, several props from the shooting set was stolen. In 2021, screenwriters Marcus Dunstan and Patrick Melton confirmed that a sequel will not be happening due to creative disinterest between them and the producers, but Dunstan and Melton shared some BTS photos of the abandoned project in May 2021.
Juan Fernández, the actor who previously played The Collector in the first movie, was unavailable to reprise his role for the sequel. In this film, the antagonist is instead portrayed by Randall Archer.
The house owned by Elena and her father, is the same house belonging to the Yakavetta crime family shown in The Boondocks Saints 2.
John Gulager: (at around 17 mins) If you look closely at the police arresting Arkin in the hospital, one of them is horror director John Gulager who has collaborated with Marcus Dunstan on other films.