In Orlando, "Harry Potter" is split between two parks ( Diagon Alley in Universal Studios Florida and Hogsmeade in Islands of Adventure). You must have a Park-to-Park ticket to ride the Hogwarts Express between them.
You can buy tickets in person at 214 W. 43rd St. to avoid online service fees. 🎬 Warner Bros. Studio Tours (London & Tokyo)
Tickets must be booked in advance at the Official UK Site . They often sell out months ahead, so plan early.