You have a manuscript, a cover in progress, and a publishing account. Then you reach the ISBN field—and discover that a single number can cost more than you expected. Before you pay, it helps to know what you need, where to get it, and which options fit your publishing plans.
Key Takeaways
- Use the official ISBN agency for the country where you are based; U.S. authors can start with Bowker.
- Compare your own ISBN with a platform-provided number around imprint and usage requirements.
- Plan the book formats and editions you will publish before deciding how many numbers to buy.
- Check distribution compatibility, metadata, and barcode needs before assigning an ISBN.
Table of Contents
- Where can you buy an ISBN for self-publishing?
- How much does an ISBN cost?
- Should you buy your own ISBN or use a free one?
- How many ISBNs does your book need?
- Can you use the same ISBN on KDP and IngramSpark?
- How to buy and register an ISBN through Bowker
- Do you need to buy a barcode too?
- Where do you get ISBNs outside the United States?
- Common ISBN mistakes to avoid
- Plan the assignments before choosing the quantity to buy
- Resolve identity mismatches before submitting the files
- Frequently asked questions
- Choose the ISBN option that fits your publishing plans
Where can you buy an ISBN for self-publishing?
Bowker: the official U.S. ISBN agency
Bowker sells ISBNs directly through MyIdentifiers.com. You can purchase a single number or a larger pack, then assign each number to a specific book format. This is a straightforward place to start if you want to manage ISBNs for several books under your own publishing name.
IngramSpark: a paid single-ISBN option
According to IngramSpark’s current FAQ, U.S. authors can purchase an ISBN to own for $85 while setting up a book in their account. That is a separate option from the free ISBN IngramSpark provides. If you only need one number and already plan to use IngramSpark, compare this price with Bowker’s single-ISBN price before purchasing.
How much does an ISBN cost?
Bowker’s listed ISBN-only prices are:
| Number of ISBNs | Total price | Cost per ISBN |
|---|---|---|
| 1 | $125 | $125.00 |
| 10 | $295 | $29.50 |
| 100 | $575 | $5.75 |
| 1,000 | $1,500 | $1.50 |
Prices checked October 11, 2026. These are listed ISBN prices; promotional offers and optional bundles may differ.
A lower price per number only helps if the larger purchase fits your plans. Three individual ISBNs at Bowker’s listed price would cost $375, while a ten-pack costs $295. But two $85 ISBNs through IngramSpark would total $170. Count the formats and upcoming books you actually expect to publish before deciding.
Include this purchase alongside editing, cover design, formatting, and proof copies in your self-publishing cost breakdown. A larger ISBN pack should earn its place in the budget.
Should you buy your own ISBN or use a free one?
A free ISBN can be a sensible way to reduce upfront costs. Buying your own gives you more control over the publishing name attached to your book and the services you use for that edition. Here is how the main U.S. options compare:
| ISBN option | Cost | Publishing name | Where you can use that ISBN |
|---|---|---|---|
| Your own purchased ISBN | Depends on seller and quantity | Your registered publishing imprint | Multiple compatible publishing services for the same format and edition |
| Free KDP ISBN | $0 | Independently published | KDP only |
| Free IngramSpark ISBN | $0 | Indy Pub | IngramSpark only |
KDP explains its free ISBN and imprint rules here. IngramSpark explains its free ISBN terms here.
These limits concern where you can upload and publish using that number. They do not mean that only one retail website can sell your book; a platform’s distribution network may make it available through other retailers.
For example, a free KDP ISBN may suit an author releasing a paperback through KDP. An author who wants the same paperback edition set up directly on both KDP and IngramSpark should use their own ISBN. Neither choice measures the quality of the writing, editing, or cover.
For help putting this decision into a wider publishing plan, browse our best books on publishing guide.
How many ISBNs does your book need?
An ISBN identifies a particular publication, including its format and edition. A paperback and a hardcover need separate numbers. If you assign an ISBN to an ebook, that number must be separate from the print editions.
- Paperback: one ISBN for that edition.
- Hardcover: a different ISBN for that edition.
- Ebook: check your distributor’s requirements. KDP does not require an ISBN for a Kindle ebook; it uses an Amazon identifier instead.
- Another book in your series: its own ISBN for each format that needs one.
A paperback and hardcover release therefore needs two print ISBNs. Do not add an ebook ISBN to your shopping list automatically if you are only publishing the digital edition through Kindle. KDP also has separate rules for low-content books such as journals, which are not eligible for its free ISBNs.
See KDP’s ISBN requirements and the International ISBN Agency’s assignment guidance for format and edition rules.
Can you use the same ISBN on KDP and IngramSpark?
Yes, if you own the ISBN and both services are publishing the same format and edition. Your title, author, imprint, and book specifications should agree across the records. You cannot share one number between a paperback and hardcover, or bring a free KDP ISBN into IngramSpark.
If you use both services for print, IngramSpark advises leaving KDP’s Expanded Distribution unselected. This keeps the distribution arrangements from conflicting. An ISBN identifies the edition; it does not need to change simply because that edition is sold by another retailer.
How to buy and register an ISBN through Bowker
Decide on your author name, book title, and publishing imprint before completing the records. Then work through these steps:
- Visit MyIdentifiers.com. Create an account or sign in, and check the current ISBN offers.
- Choose the quantity. Use your planned formats and future titles to decide between a single ISBN and a pack.
- Assign an unused ISBN to the right edition. Keep separate records for paperback, hardcover, and any digital formats you register.
- Complete the title information. Enter the title, author, format, subject, price, and other relevant publication details accurately.
- Submit the title assignment. Purchasing numbers alone does not complete your book’s catalog information.
- Match the publishing-platform fields. Copy the registered title, author, and imprint carefully when you enter your own ISBN into KDP or another service.
Bowker’s title assignment instructions explain the registration process. KDP also checks that your imprint matches the ISBN agency’s record, so spelling, capitalization, and stray spaces matter.
Before approving your final files, check that the correct ISBN appears on the copyright page and matches the back-cover barcode. Add this to your ebook and paperback proofing checklist.
Do you need to buy a barcode too?
An ISBN is the identifying number. A barcode is the scannable graphic that represents it. They are related, but purchasing an ISBN does not automatically mean you need to pay separately for a barcode.
KDP can add a barcode to your print cover if you do not supply one. IngramSpark’s cover template generator also provides a barcode. Check your printer’s cover requirements before buying an ISBN-and-barcode bundle, and leave the required space clear in your cover design.
Where do you get ISBNs outside the United States?
The correct agency usually depends on where the publisher is based, rather than where the book is printed or where readers buy it. Start with the International ISBN Agency directory if you are unsure.
| Where you are based | Where to start | What to check |
|---|---|---|
| United Kingdom or Ireland | Nielsen ISBN Store | Current packages and eligibility |
| Canada | ISBN Canada eligibility guidance | Free ISBNs for eligible Canadian publishers; French-only publishers are directed to BAnQ |
| Australia | Agency directory: Thorpe-Bowker | Current Australian pricing and registration rules |
| Other countries | International ISBN Agency directory | The agency responsible for your country or territory |
Canada’s free service has eligibility requirements. It is not a workaround for a U.S. author who wants to avoid paying a U.S. agency. Follow the rules of the agency that serves your location.
Common ISBN mistakes to avoid
- Buying a cheap number without checking the publisher of record. An unauthorized reseller’s number may identify that reseller as the publisher. Bowker’s ISBN FAQ explains this problem.
- Using one number for different formats. Readers and booksellers need to distinguish a paperback from a hardcover.
- Reassigning a used number to your next book. A published edition keeps its ISBN, even if it goes out of print.
- Assuming every update requires a new ISBN. The International ISBN Agency says a price change does not; a substantial revision, new format, or title change does.
Plan the assignments before choosing the quantity to buy
List actual titles and intended formats rather than estimating from the number of manuscripts. A print-format plan can require more identifiers than a title count alone suggests.
| Illustrative catalog | Paperback assignments | Hardcover assignments |
|---|---|---|
| Book one | 1 | 1 |
| Book two | 1 | 1 |
| Book three | 1 | 1 |
| Total planned print assignments | 3 | 3 |
That example requires six distinct print-format assignments. If you also choose or need to assign an ISBN to each ebook, add those separately. KDP’s ISBN guidance says ebooks can use an optional ISBN, while paperback and hardcover formats need distinct numbers. Check another distributor’s requirements before assuming the same workflow applies there.
Mark each entry as confirmed, proposed, or deferred. A possible future hardback can inform a purchase comparison without being treated as a committed release. Keep unassigned numbers apart from identifiers already attached to published editions.
The International ISBN Agency’s assignment guidance explains format and edition distinctions and says an out-of-print edition’s number should not be reassigned to another publication. Keep a permanent assignment ledger even when a book leaves active distribution.
Resolve identity mismatches before submitting the files
Use one authoritative record for the title, author, imprint, format, and assigned ISBN. Compare it with the agency record, publishing setup, copyright page, and cover or barcode where the identifier appears.
- Confirm that the number belongs to this title and edition.
- Confirm that the format matches the planned product.
- Compare the exact title, author, and imprint entries.
- Check every place the number appears in the files.
- Save the approved record with the final publishing files.
KDP checks an owned ISBN’s imprint against the agency record and notes that case and extra spaces can cause mismatches. If an error appears, compare the actual entries before buying another number or changing the publisher name to a placeholder.
Keep the source of the identifier visible too: agency-purchased, platform-provided, or another documented arrangement. A platform’s free number is not interchangeable with one you own for use elsewhere. Confirm the appropriate route before building a second distribution setup around it.
This ledger also helps when a series grows. You can see which formats already exist, which assignments remain available, and which planned releases need a fresh check of agency and platform requirements.
Frequently asked questions
Do unused ISBNs expire?
Bowker says its ISBNs do not expire, so unused numbers can be kept for later releases. Once a number has identified a published edition, it cannot be recycled for another book.
Can I replace a free ISBN after my book is published?
On KDP, you cannot change the ISBN of a published book in place. KDP requires a new edition if you need to change it. Choosing before launch can save you from repeating setup and proofing work.
Does buying an ISBN register my copyright?
No. ISBN assignment identifies a publication in the book trade. Copyright registration is a separate process; the U.S. Copyright Office explains copyright protection and registration.
Choose the ISBN option that fits your publishing plans
For U.S. authors, Bowker is the direct agency option, while IngramSpark offers a lower listed single-ISBN price during setup. A pack becomes more useful when you have several formats or books planned. A free platform ISBN may suit a smaller release if its imprint and usage limits fit your goals.
Start with the formats you will actually publish, decide which services you want to use, and choose the publishing name you want attached to the book. With those decisions made, the ISBN purchase becomes a clear budget choice instead of another confusing launch expense.