An ISBN is an International Standard Book Number, found on every published book and contains a series of unique numbers.


“An ISBN is assigned to each separate edition and variation (except reprintings) of a publication.”


The ISBN is usually found on the back of a book and is accompanied by a barcode. So, why do you need to know the difference between ISBN 10 and ISBN 13?

What Are ISBN 10 and ISBN 13?

ISBN-10 and ISBN-13 indicate how many digits are in the ISBN and are two separate systems for identifying books. Before 2007, there were only 10-digit ISBNs; thereafter, 13-digit ISBNs were introduced and used to increase the availability of ISBNs worldwide. Technically, books published earlier than January 2007 have both ISBN-1o and ISBN-13. Books published later than January 2007 have only ISBN-13. Basically, a book’s ISBN-10 and ISBN-13 are two similar sets of numbers. Their middle numbers are the same, but they differ in length and have different beginning numbers and check digits (last numbers).

  • ISBN-10 is a 10-digit number that begins with a group identifier (e.g., 1 or 0), which identifies a country, geographical, or language area. It ends with a check digit (never identical to the one in ISBN-13 ).
  • ISBN-13 is a 13-digit number that begins with the prefix—978 or 979—and ends with a check digit (never identical to the one in ISBN- 10).

“To date, 13-digit ISBNs assigned by the U.S. ISBN Agency include the 978 prefixes, which allowed systems to contain both 10- and 13-digit ISBNs for all books. However, a 13-digit ISBN starting with 979 does not have an equivalent 10-digit ISBN.”

It means that books containing just the 979 ISBN-13 number don’t have corresponding ISBN10s and can only be found on newer systems and new books published after 2020.


Each ISBN-10 has four sections, like in this example, ISBN 0-061-96436-0. Each section has a different meaning:

  • The group identifier identifies the country or region it has been published.
  • The publisher identifier represents the publisher of the book.  
  • The title identifier identifies the book edition. It may have up to six digits and helps ensure the ISBN is 10 digits long. 
  • The check digit is created using the first nine digits in the ISBN and is used to check its accuracy.


Each ISBN-13 has five sections, like in this example, ISBN 978-0-061-96436-7. Apart from the prefix element and the check digit, all sections relate to the ISBN 10.

  • The prefix element is 3 digits long, making the ISBN a universal product code called an EAN.
  • The registration group identifies the country or region the book is published. 
  • The registrant element identifies the publisher. 
  • The publication element identifies the style of the publication. 
  • The check digit is calculated in a similar way as the ISBN 10. 

To generate an ISBN 13 from an ISBN 10, you can use this website. It will also generate the new barcode image for your ISBN.

What if You Can’t Find the ISBN Number?

Since 1970 books in the US have been assigned an ISBN; before this date, they may have had a standard book number or no numbers at all. You can try and locate the ISBN by using other information you have, such as the book’s title, author, and date of publication. If you still can’t locate the ISBN number, it may be worth taking your book to a dealer to see if it is a rare book and worth some money.