Harry Potter and the Cursed Child, the two-part new play co-created by J.K. Rowling, Jack Thorne and John Tiffany that tells an original eighth "Harry Potter" story, is reported to have already taken £20 million at the box office — just over a week after tickets went on sale to those who had registered for priority booking on the show's website.
SOURCE: Playbill at 12:06PM on November 6, 2015