Every book needs an ISBN (International Standard Book Number). This is the black and white lined graphic (with 13 numbers underneath) that appears on the back of the book jacket.
If you are writing or have written a book I can supply you with your unique ISBN.
They’re just £57 each. You only need one per book.
But I have a FREE Amazon CreateSpace ISBN, do I need another one?
Yes. If you’re using a FREE ISBN number from Amazon to sell on their site you won’t be able to use the ISBN outside of their online store. More details here.