How to place the ISBN number on the back of a book cover.Use Affinity Publisher.

If you want to publish a paperback or other type of book, you will need an ISBN number. This is a number that identifies the book. If you want to be the publisher of your book, you have to purchase the number yourself, but you can also let KDP place one on the back of your book. In that case, KDP owns the ISBN and is therefore the publisher of the book. While you retain the rights to your written work, you cannot publish your book with that particular ISBN anywhere other than with KDP.

Photo from Wix collection

I bought a package of ten ISBN numbers from ISBN.nl because it was much cheaper than buying just one.

One number costs €109 excluding 21% tax, whereas ten numbers cost €297 excluding 21% tax. To publish an ebook, paperback and hardcover versions of a book, you will need at least three ISBN numbers.

Purchasing the ISBN-number

I created an account at isbn.nl. But first, I needed a prefix number. This is a number used by publishers. To obtain one, I had to register my own publishing house with the Chamber of Commerce. I decided to go for a cool name: Uitgeverij Huis van Mercurius ('House of Mercury Publishing').

Register the books

When I decided to publish a paperback, hardcover and ebook edition, I registered the ISBNs at isbn.nl. Then I decided to create another paperback version with illustrations, a map of the world and a photo of me on the last page. I therefore had to register this version of the book at isbn.nl too.

So far I have registered the following numbers:

Officially published at 1 September 2025

9789083552033 Hardcover the Power of the Diamond.

Printing On Demand via Kindle Direct Publishing.

Ready for pre ordering at 1 August 2025 at Amazone.com.

Officially published at 7 October 2025

9789083552002 EBook the Power of the Diamond.

Ready for pre ordering now at Kobo.com and at Amazone.uk.

97890835520267 Paperback the Power of the Diamond.

Printed and bound by New Energy Printing, Vianen, the Netherlands.

9789083552057 Paperback the Power of the Diamond with illustrations.

Printing On Demand via Kindle Direct Publishing.

This is how I placed the ISBN number on the back cover

Tip #1 - Create a vector file with barcodesvg.com.

Go to the website of barcodesvg.com and fill in the ISBN number. Then click 'Generate Barcode'. Download the file as a vector file. The extention is .gif

Tip #2 - Go to the bookcover file in Affinity Pub

Place the vector file in the document and with the help of the template of KDP - see my previous post - you can adjust the picture to the recommended sizes.

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