Though Rowling did not create the game's characters or story, as the author of Harry Potter she owns the rights to the franchise's intellectual property, meaning that she makes royalties based on Harry Potter merchandise, the movies, the Warner Brothers theme park, and of course, sales of the books.

J.K. Rowling’s royalty streams in 2026 are incredibly diverse, extending far beyond her original seven Harry Potter books. She earns significant percentages from book sales (including digital and audio versions via Pottermore/Wizarding World), the Fantastic Beasts film franchise, and the global stage production of Harry Potter and the Cursed Child. She also receives "licensing royalties" from the Universal Studios theme parks (The Wizarding World of Harry Potter) in Orlando, Hollywood, Japan, and Beijing. Furthermore, she earns from a vast array of merchandise, ranging from LEGO sets and apparel to high-end collectibles. In recent years, her royalties have also included revenue from the Hogwarts Legacy video game and the new HBO Harry Potter television series currently in production, ensuring a continuous flow of income from every facet of her literary and cinematic universe.