As said by others, really depends on what the publisher provides. They may have different geographic versions of the book, for example; US / Canada and UK versions, and so the UK version gets UK English (or proper English, depending on you viewpoint
) and US / Canada gets the US English. You may also find that different publishers are used for different countries, and that may also mean different "English" versions of the book.
Again as mentioned, Harry Potter is a good example of where US / Canada gets the US English version, and UK gets the British English version. Booger vs Bogey was a good example of differences in the language.