J.M. Barrie generously gave all the rights to Peter Pan to Great Ormond Street Hospital in 1929, and this was later confirmed when he died in 1937.
Since then the hospital has received royalties every time a production of the play is put on, as well as from the sale of Peter Pan books and other products.
You can get all the information you need on rights from GOSH.org
This is from their FAQ page: http://www.gosh.org/about-us/peter-pan/faqs
Does Great Ormond Street Hospital have the copyright in Peter Pan in perpetuity?
No, the hospital has a right to royalty in perpetuity in the UK, but this is not a true copyright. This right was granted to the hospital by the Copyright Designs & Patents Act (1988) (CDPA) and applies to stage productions, broadcasting and publication of the whole or any substantial part of the work or an adaptation of it in the UK. This right does not apply to derivative works such as sequels, prequels, spin-offs or to extracts.
The play Peter Pan is in copyright in the US until 2023, and in Spain until 2017. This applies to stage adaptations of the story.
The copyright has expired everywhere else so, apart from the play in the US and Spain, it is considered in the public domain.
Can anyone now write a sequel, prequel or other spin-off using the characters from the original story of Peter Pan?
Yes, because in the UK the terms of the CDPA (see above) do not apply to derivative works.
So, there you go! You can download and read LOVE, TINK with a clear conscience. :)
Free until Nov 2