The ISBN is already in 13-digit format and can be represented easily as a bar code. Bar coded ISBNs may assist distributors and retailers in stocking and selling your publication. Your national ISBN agency should be able to provide advice on bar code suppliers to help you show your ISBN as a bar code graphic. To maximise the benefits of bar code recognition and scanning speed it is recommended to print the bar code on the lower right of the outside back cover of the publication.
GS1 is the global organisation responsible for product identification systems such as bar coding which is used to improve the efficiency of the supply chain. If you only want to use the ISBN in bar-coded form, you do not have to become a member of GS1 in order to do so. However, as GS1 provides other trade-related services, such as electronic address numbers (location codes), EDI (electronic data interchange) formats, etc., you may want to become a member. Check with GS1 for information on their services and for details of current member organisations.