If you are researching book publishing, you may have noticed that some books have an ISBN 10 while newer books use an ISBN 13. This can make it confusing to understand whether they identify different books or simply represent the same ISBN in different formats. So, what is the difference between ISBN 10 and ISBN 13?
The main difference is that ISBN 10 is the older 10-digit format, while ISBN 13 is the current 13-digit standard. ISBNs were 10 digits through December 2006, and the ISBN system switched to 13 digits on January 1, 2007. Today, newly assigned ISBNs are 13 digits long.
Although the two formats look different, an ISBN 10 and its corresponding ISBN 13 can identify the same edition of a book. The numbering system changed to provide greater capacity and to align ISBNs with the product identification systems used in the wider retail industry.
What Is an ISBN?
ISBN stands for International Standard Book Number. It is a unique identifier used to identify a specific book or other eligible book product, including its publisher, edition, and format. Publishers, booksellers, libraries, distributors, and online retailers use ISBNs to identify and manage books throughout the publishing and retail supply chain.
An ISBN is not the same as a barcode. An ISBN is the identifying number itself, while a barcode is a machine-readable representation that can be printed on a book and scanned by retailers or distributors.
An important point for authors is that an ISBN is associated with a specific edition and format. For example, a paperback and hardcover version of the same title generally require separate ISBNs. A new edition also receives a new ISBN because it is treated as a different product.
What Is the Difference Between ISBN 10 and ISBN 13?
The simplest way to understand the difference between ISBN 10 and ISBN 13 is to look at their length and structure. ISBN 10 contains 10 characters, while ISBN 13 contains 13 digits. ISBN 10 was the standard format used before the 2007 transition, whereas ISBN 13 is the current standard for ISBNs.
ISBN 13 also contains a three-digit prefix at the beginning. Current ISBN prefixes are 978 or 979. This prefix is followed by elements that identify the registration group, publisher or registrant, specific publication, and finally the check digit.
ISBN 10 has a different structure because it predates the addition of the three-digit prefix. Its check digit system is also different. One of the most noticeable characteristics of ISBN 10 is that its final check digit can sometimes be represented by the letter X, which represents the value 10. ISBN 13 uses a numeric check digit.
Why Did ISBN 10 Change to ISBN 13?
The transition from ISBN 10 to ISBN 13 was made because the 10-digit system was approaching its available capacity. The change also allowed ISBNs to work more closely with the EAN 13 product identification system used in retail.
The ISBN system officially moved to the 13-digit format on January 1, 2007. This gave the publishing industry a larger numbering capacity while creating better compatibility with international product identification and retail systems.
This is why authors publishing books today will normally encounter ISBN 13 rather than ISBN 10. Older books may still display their original ISBN 10 because those numbers remain useful for identifying historical publications and editions.
What Does an ISBN 13 Look Like?
An ISBN 13 is made up of five elements. The first is the three digit prefix, which is currently 978 or 979. The next elements identify the registration group, publisher or registrant, and specific publication. The final digit is the check digit used to validate the ISBN.
For example, an ISBN 13 may appear in this format:
978-0-123-45678-6
The hyphens are used to make the number easier to read. They are not additional characters that change the ISBN.
The structure allows the ISBN to communicate information about the publication while providing a unique identifier that can be used throughout the book industry.
Can You Convert ISBN 10 to ISBN 13?
Yes, an eligible ISBN 10 can be converted to its corresponding ISBN 13. However, conversion is not as simple as placing three numbers at the beginning of the existing ISBN.
For a 978 based ISBN, the conversion process involves removing the ISBN 10 check digit, adding the 978 prefixes to the remaining digits, and calculating a new ISBN 13 check digit. The final digit may therefore be different from the original ISBN 10 check digit. The official ISBN Agency provides a calculator for converting older 10-digit ISBNs into their correct 13-digit counterparts.
ISBNs beginning with the 979 prefixes do not follow the same conversion process from ISBN 10 because the 979 prefix was introduced within the ISBN 13 system.
For authors who need to verify or convert an existing ISBN, using an official ISBN resource is preferable to simply adding 978 to the beginning of the number.
Are ISBN 10 and ISBN 13 the Same?
ISBN 10 and ISBN 13 are not literally the same number because they contain different numbers of digits and use different check digit systems. However, an older ISBN 10 can have a corresponding ISBN 13 that identifies the same publication edition.
This is why you may find both an ISBN 10 and ISBN 13 listed for an older book. The two numbers can represent the same edition in different ISBN formats rather than representing two completely different books.
The distinction becomes particularly important when searching for books in catalogs, retailer databases, library systems, and publishing platforms. Using the correct ISBN format can make it easier to locate the exact edition or format you are looking for.
Which ISBN Should a New Author Use?
If you are publishing a new book today, ISBN 13 is the format you should expect to use. The ISBN system now uses 13-digit numbers for newly assigned ISBNs.
Authors should also remember that an ISBN is connected to a particular edition and format. If you publish the same title in paperback, hardcover, and ebook formats, each format may require its own ISBN depending on the applicable ISBN rules. The ISBN Agency explains that each different product form should be identified separately.
If you are preparing a manuscript for publication and need help understanding the broader publishing process, you can explore our book publishing services to learn more about the professional support available to authors.
Does an ISBN Protect Your Copyright?
An ISBN identifies a book or book product, but it does not provide copyright protection. These are two separate concepts. An ISBN helps publishers, booksellers, libraries, and distributors identify a publication, while copyright concerns the legal protection of original creative work.
Understanding this distinction is important for new authors because obtaining an ISBN should not be viewed as registering copyright for a manuscript.
How Much Does an ISBN Cost?
The cost of obtaining an ISBN depends on the country where the publisher or self-publisher is based and the ISBN agency responsible for assigning numbers. In the United States, ISBNs are assigned through the U.S. ISBN Agency.
If you are planning to publish a book and want to understand the expenses involved, read our detailed guide on how much an ISBN costs. It explains the costs authors should consider when obtaining an ISBN and planning their publishing budget.
Frequently Asked Questions About ISBN 10 and ISBN 13
What is the difference between ISBN 10 and ISBN 13?
ISBN 10 is the older 10-digit ISBN format, while ISBN 13 is the current 13-digit format. The ISBN system changed to 13 digits on January 1, 2007. ISBN 13 also uses a 978 or 979 prefix and has a different check digit calculation from ISBN 10.
Are ISBN 10 and ISBN 13 the same?
They are different numerical formats, but an ISBN 10 can have a corresponding ISBN 13 that identifies the same edition of a book. The ISBN 13 version has a different structure and requires its own check digit calculation.
What is the difference between ISBN 10 and ISBN 13 check digits?
ISBN 10 uses a different validation method and can have X as its final check digit. ISBN 13 uses a numeric check digit calculated using the ISBN 13 validation system.
Can ISBN 10 be converted to ISBN 13?
Yes, eligible ISBN 10 numbers can be converted to ISBN 13. For a 978 based ISBN 10, the conversion involves adding the 978 prefix and recalculating the final check digit. Simply adding 978 without recalculating the final digit does not produce a valid ISBN 13.
Do new books use ISBN 10 or ISBN 13?
New ISBNs are issued in the 13-digit format. ISBN 10 is primarily encountered with older publications that were assigned ISBNs before the 2007 transition.
Why does my book have both an ISBN 10 and ISBN 13?
An older book may have both because its original ISBN 10 can have a corresponding ISBN 13 representation. Listing both can make it easier for different cataloging, retail, library, and publishing systems to identify the same publication.
Final Thoughts
The difference between ISBN 10 and ISBN 13 comes down to the evolution of the International Standard Book Number system. ISBN 10 was the older 10-digit format, while ISBN 13 became the standard on January 1, 2007. ISBN 13 uses a 978 or 979 prefix, contains a different check digit system, and provides greater numbering capacity for the modern publishing industry.
For authors publishing a new book, ISBN 13 is the format that matters today. If you are researching an older publication, however, you may still encounter ISBN 10. Knowing how the two formats relate can help you identify books accurately, understand publishing requirements, and avoid confusion when preparing your own book for publication.
