|How to Enter a ISBN number|
International Standard Book Numbers (ISBNs) are numbers used to identify books and book-like products (such as audio books). Find your ISBN on your product's back cover.
The ISBN is usually preceded by the letters "ISBN" and is divided into four parts. When entering the ISBN for a listing using Pre-Filled Item Information, be sure to include all the numbers in each part. Beginning January 1, 2007, all books will be identified by a 13-digit ISBN. However, you can enter either the old 10-digit or new 13-digit ISBN, if one or both numbers are available.
In many cases, eBay only has access to the information relating to the latest version of the product. Older editions may have different ISBNs. As a result, you may be unable to find an item by ISBN. As always, you can list any item the ordinary way, without using Pre-Filled Item Information.