What is an International Standard Book Number (ISBN)
ISBN (International Standard Book Number) is a type of GTIN (Global Trade Item Number) used to uniquely identify books and similar publications. It’s a 13-digit code assigned to a specific edition and format, making it easier for publishers, retailers, and libraries to manage and track inventory.
Examples
| Format | Example | Notes |
|---|---|---|
| ISBN-13 | 9783161484100 | Common modern format (GTIN-13) |
| ISBN-10 | 316148410X | Older format, still used in some databases |
Good to know
In 2007, the ISBN system switched from 10 to 13 digits to align with international GTIN standards. Most books published before then have since been updated with a 13-digit ISBN, and you’ll often see both formats listed together, especially in online catalogs or barcode areas. The content stays the same; it’s just the format that changed.
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Frequently Asked Questions
Do all books have an ISBN?
Not necessarily. ISBNs are assigned to books intended for commercial distribution. Self-published, custom, or digital-only publications might not have one unless the publisher chooses to assign it.
Can two books have the same ISBN?
No. Each ISBN is unique to a specific edition and format of a book. For example, the hardcover and paperback versions of the same title will each have a different ISBN.
Where can I find the ISBN on a book?
Most printed books show the ISBN on the back cover near the barcode, and often on the copyright page inside. For ebooks, it's typically listed in the metadata or digital product description.
Can I use the same ISBN for different formats of a book?
No. Each format, like hardcover, paperback, and ebook, should have its own unique ISBN. That’s because the ISBN is used to identify not just the title, but also the specific version being sold or distributed.