ISBNs: Do self-publishers need them?

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flickr credit: ryoki

Planning on self-publishing?

Started the process and feeling overwhelmed by all you didn’t know?

Confused by all the little details?

Said yes to one too many? Perhaps you’re spending much of your time learning the ropes. The learning curve can be steep, and I’ve posted a few lists of resources to help. One area that seems to cause a lot of bewilderment is the ISBN.

The continuing confusion over ISBNs

The Book Designer’s guide for self-publishers explains that each format needs its own ISBN, including Kindle, epub, and PDF. BookBaby also has a guide for writers, and says “every book — physical or eBook — is required to have its own number.”

Sounds simple. But there’s contradictory advice out there. The Indie Author Guide explains that every printed book must have its own ISBN. But the rules are a bit different for ebooks, since they’re really digital files. If you’re not confused yet, go to the Kindle site. Kindle explains that they don’t require an ISBN when you register a book at their site. They’ll assign their own number (ASIN, Amazon Standard Identification Number) to a file without an ISBN. Barnes & Noble’s PubIt! Service has the same policy.

The International ISBN Agency recommends a unique ISBN for each format (epub or PDF). But if there are different versions on the same format, they should have the same ISBN.

Wait! Come back! Don’t give up yet…

The blog Publetariat made a point that really helped me figure this out. Amazon’s Kindle uses only mobi files, and so it makes sense that you don’t need an ISBN because you will only be using the mobi file at Amazon. There’s no potential to confuse it with a mobi file somewhere else. So, if you only make your ebook available at Amazon, there’s really no need for an ISBN. The ASIN will identify the book.

But you want to distribute everywhere, you say?

The trick is this: while Kindle only uses mobi files, Kindle converts Word, PDF, text, rich text format, HTML, and epub. Yes, that’s right, you can submit an epub file to Kindle that they will convert to their format. So when a friend who recently self-published explained to me that she only needed one ISBN because all of her ebook files were in the epub format, it clicked. If she had an epub file and a mobi file, then she’d need two ISBNs. But using only the epub, she only needed the one for that ebook. Thanks, Jennifer, for the insight!

If you’re distributing with multiple distributors (and so using the epub format), it’s advisable to get the ISBN. And some distributors will require it (like Apple). But you still only need one.

So, how many ISBNs should you buy?

Many sites will say, one for each book. But what they mean is, one for each format. If you publish your book in print, ebook (epub format), and as an audiobook, that’s three ISBNs. Which means, buying the 10-pack is still the best deal, as buying two individually cost as many as buying ten.

I’ll note that none of the sites I mentioned actually had their info wrong. It’s just that there are subtleties in what’s being said that are easily missed that can cause — and have caused — a lot of confusion.

Remember that retailers use the ISBN to identify and track your book. To maximize your profits and maintain control over your work, you need to be the “publisher of record.” You do this by buying your own ISBN. When you accept the free ISBN offered by CreateSpace, you are not the “publisher of record.” CreateSpace is.

So the ISBN is your friend. Don’t cut corners here.

Have you approached the ISBN issue any differently? Did you buy one for your latest publication? How many did you buy? Let me know your thoughts in the comments.


  1. Dianne Greenlay

    Monica, thanks so much for this clarifying post on a very confusing subject! I am a Canadian author who published through CreateSpace first time around but for the next book I will go the complete indie route, including using my own ISBN. Just wondering: in Canada, ISBN’s are available for free – does it matter what country they are obtained from when publishing on Amazon and with, say, Smashwords or Book Baby?

    • monica4567

      Hi Dianne!
      I’m so glad you found the post helpful. I found so much conflicting info out there I wanted to know myself what the real deal was.
      According to Bowker, the US ISBN agency, it doesn’t matter where you get the ISBN. The number itself is international. It only matters where the publisher is located. And in their words, “There is no such thing as a US ISBN. ISBNs are international, but assigned locally.” If you want to read more on that, visit
      I certainly am curious (and maybe a bit jealous) about your free Canadian ISBNs. They’re just assigned to your book at no fee, huh? Figures. Here we have to pay for everything.

  2. Alyssa

    Very good post and very helpful. But I’m still a little bit confused. I looked up whether I needed an ISBN before, but didn’t understand it that time around either.

    Long story short, is an ISBN absolutely necessary for a self published book at say, Amazon? I don’t think so, because it said it assigns their own. But what about selling ebooks at other places? Do I need an ISBN for each place I sell my book at?

    One more thing, what does the “Publisher of record mean”? And it is important? I’m asking all these questions because at the moment, it’s utterly impossible to buy any sort of ISBN due to the price. So long story short, is it honestly necessary?

    Whew long comment. I’ll stop here. Thank you so much for putting all this info in one place, it’s a very good go to reference for ISBN questions.

    • monica4567

      Hi Alyssa! Thanks for stopping by!
      I definitely understand the money concerns. You are right — Amazon will assign their own number. If you’re only selling there, you definitely don’t need one.
      Apple is the one place I found that requires an ISBN. Other sites recommend it but don’t require it. Why do they recommend it? Because of that pesky “publisher of record” thing. As I understand it, the publisher of record is the legal owner of the work. So for legal reasons, which lead into issues Cyrus raised in his comment above, this is important. It’s also important because it’s the number used by retailers to track your book. It makes sure they have the correct version of your book for a sale. I suppose, theoretically, that would mean, IF you only have one format out there, the ISBN wouldn’t be of much help. So if you’re only doing an ebook, that you have in epub format, you might get away with skipping this step.
      Now I’m wondering if you can get an ISBN after a book has been published. I’ll have to look into that.

      • monica4567

        Hi again Alyssa,
        I wanted to add that I found out you can assign an ISBN to a book that’s already been published. So theoretically, you could publish your book now and buy an ISBN when you’re able to. Just thought you might want to know.

  3. Cyrus Keith

    One thing to add, from a contract published author’s POV, but nonetheless valid. This is critical: You CAN NOT register a U.S. copyright without an ISBN for the format you are registering. Why that is critical is that although you don’t absolutely have to register your copyright (which is not the same as owning copyright), registering gives you the ability to pursue punitive damages in court. That gives you just that much more ammo against piracy and plagiarism. Registering only costs 35 dollars on line.It’s worth every penny, folks.

    • monica4567

      Great point, Cyrus. Thank you for adding that. While I do recommend all authors assign an ISBN to their work, it’s reality that it may be impossible for some to do so. But I’m glad to know the cost of registering your work with the US copyright office. Thanks again for stopping by!

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