Books within the same batch as the one that just sold are instantly recognisable because of two distinctive typos, one of which can be seen from the outside. First, check the back cover where (if the book is a limited edition copy) the word “philosopher” will be spelled wrong.

Next, flick to page 53 where a supply list of magical items has an accidental repeat of “1 wand”. Instead of being referred to as JK Rowling, on the earlier printed editions the author is known as Joanne. And finally, the publisher must be Bloomsbury, the date on the copyright page must be 1997 and the print line on the page must read: “10 9 8 7 6 5 4 3 2 1.”

Although the owner of the book which sold at auction has decided to stay anonymous, it is reported by CNN that she invited Hansons Auctioneers in Staffordshire to value a large amount of books, include the rare Harry Potter tome.

Jill Gallone, head of media at Hansons Auctioneers, spoke to the news outlet outlining the above tips for spotting a rare edition and confirming that these editions are considered rare because many went to schools and libraries, as Rowling’s masterpiece wasn’t nearly as celebrated then.

Gallone says: “When the owner bought it all those years ago, nobody knew that Harry Potter would turn out to be this popular.”

Your old Harry Potter books could be worth a fortune if they have this typo