The expiry of the copyright on Anne Frank’s diary differs from country to country, depending on the country’s copyright laws.
Is Otto Frank the co-author of the diary of Anne Frank? No, Anne Frank is the sole author of the A and B versions of the diary and the short stories. Neither Otto Frank nor any other person is co-author. Otto Frank compiled the book ‘Het Achterhuis, dagboekbrieven 14 juni 1942 – 1 augustus 1944 (‘The Secret Annexe, diary letters 14 June 1942 - 1 August 1944’), published in the Netherlands in 1947, from the initial (‘A’) version and the rewritten (‘B’) version of Anne’s diary. Subsequent trade editions were based on this edition. Otto had to use a combination of both of Anne’s versions because the A version is incomplete and the B version ends before 1 August 1944. Although Otto made some editorial decisions, they remain exclusively Anne's diary entries and short stories.