Do you need your own ISBN?
An ISBN is a product code. It does not prove you wrote the book, it does not register copyright, and it does not get you into stores by itself. It is the number a retailer, a library and a distributor use to mean this exact thing and not the one next to it.
That last part is where most of the confusion lives.
One ISBN, one edition, one binding
An ISBN identifies a single edition of a single book in a single binding. Change the binding and you have changed the product, so the number changes with it.
- Paperback. Its own ISBN.
- Hardcover. A different ISBN, even with identical text.
- Large print. A different ISBN again — different trim, different page count, different physical object.
- Ebook. Its own, if your store requires one at all.
Audio is separate too. Four formats of one novel is four numbers, not one.
A reprint does not need a new one. Fixing typos, correcting a misspelled name, adjusting margins, replacing the cover art — the book is still the same edition, and it keeps its number.
What does need a new one is a new edition: substantially revised or added text, a new translation, a book re-released with new front matter and a different page count that you intend to sell as distinct from the old one. The test is whether a buyer would be annoyed to receive one when they ordered the other.
The real decision: free or your own
Every major print service will hand you an ISBN at no cost. That is not a trap, and for a lot of authors it is the right answer. But the free number is not neutral, and the differences are worth knowing before you commit.
A free printer-supplied ISBN. Takes a minute, costs nothing, and works. The printer is recorded as the publisher of record in the industry data, which is the part people underestimate — your book's listing will show their name where a publisher name goes, not yours. The number is also generally usable only at that printer. If you later move the book somewhere else, you start over with a new number there.
Your own ISBN. You buy it from the agency for your country and it belongs to you. You name the publisher, which can be your own imprint — see Should you invent a publisher name?. The same number stays with the book everywhere it goes, so moving printers, adding a second distributor, or selling direct does not fragment the book into several near-identical listings. It costs money and it takes a little admin.
The short version: one book you intend to leave where it is, free is fine. A series, an imprint, or any chance of changing printer later, and your own number saves an untangling job you cannot do retroactively.
In the Cover Maker. Type your ISBN once and the back cover is built around it — the barcode area reserved, or a real barcode with the number encoded, depending on where you are printing. Start a book → · about the Cover Maker
Ebooks are a separate question
Several ebook stores do not require an ISBN at all. They assign their own internal identifier and sell the file happily without one. If you are only selling an ebook through those stores, you may never need a number for it.
You still might want one: an ISBN lets libraries and aggregators reference the ebook independently of any one retailer's catalog. But it is a choice, not a requirement. Check each store's rules before buying a number you may not need.
Buying your own, country by country
ISBNs are assigned nationally. Each country has one designated agency, and you buy from the agency covering where you are based — not from whichever site ranks highest in search. A number bought through a reseller is usually registered to the reseller rather than to you, which defeats most of the reason to buy your own.
Two things vary by country and change over time, so check the current rules with your national agency rather than trusting a figure from an article:
- Price. Some countries charge, some supply ISBNs free to their citizens, and the fees change.
- Eligibility and terms. Who may register, what counts as a publisher, and what you are required to deposit or report.
One thing is consistent almost everywhere: numbers are cheaper per unit in blocks. Buying a single ISBN is usually the worst value on the sheet. If you have three formats of one book, you already need three.
What goes wrong
Both of these are easy to do and unpleasant to undo.
- One ISBN across formats. Printing the paperback's number on the hardcover, or reusing it for the ebook, produces listings that collide. Reviews, sales data and availability get attributed to the wrong product, and retailers will not always merge or separate them on request.
- The wrong ISBN on the copyright page. The number printed inside the book and the number registered for that binding have to match. When they do not, you get a physical object that identifies itself as something else, and the fix is a reprint. Build the page from the same data you used for the cover — see The copyright page.
Neither is a disaster. Both cost more effort than getting it right first time, which takes ten minutes and a list of which format has which number. Write that list before you upload anything, and check it against Where to print so you know whose ISBN policy you are working under.
Make yours
Everything here is built into the tools, and they are free to use: name your book, bring your manuscript or your artwork, and work as long as you like. You only pay when you want the files without the preview watermark.
Next: Barcodes, and the price code beside them · More: The copyright page · Where to print