You have to get permission from a British government department to publish the KJV in the UK. Permission is always granted, and there's no cost involved. It's just a nominal thing to satisfy the requirements of crown copyright.
EDIT: A little research reveals that it's actually the Cambridge University Press, who are the crown's "agents" for the KJV copyright, that you need to get permission from. Full details are at:
http://www.cofe.anglican.org/worship...ds/litcopy.rtf
(warning: it's an RTF file)