HBO's Harry Potter series cost up to £150M to launch, filings suggest

UK company filings for Plum Jam Productions suggest HBO's Harry Potter series could have cost as much as £150 million ($201 million) to launch, according to Deadline. The production company reported revenue of £130.6 million ($175 million) in 2025, the year the first season went into production at Warner Bros. Studios Leavesden.

The same filings show revenue of £18.4 million in 2024, when development on the series began. Based on those figures, a rough estimate puts the first season at about £18.8 million ($25.2 million) per episode.

A source told Deadline the show is expected to rank alongside the final season of Game of Thrones and The Last of Us among HBO's most expensive series. The same source said costs are front-loaded because the sets built at Leavesden are meant to serve all seven seasons.

The cast includes Dominic McLaughlin as Harry Potter, Alastair Stout as Ron Weasley, Arabella Stanton as Hermione Granger, John Lithgow as Albus Dumbledore, Paapa Essiedu as Severus Snape and Janet McTeer as Minerva McGonagall. Nick Frost plays Rubeus Hagrid, with Bel Powley and Daniel Rigby as Petunia and Vernon Dursley. J.K. Rowling wrote the source books.

HBO declined to comment. The Times of London first reported the Plum Jam Productions earnings. The company was previously called Roundabout Productions, the vehicle through which The Nevers was produced.