More details about how to assign ISBNs

•  Assigning ISBNs to different language editions 

Each different language edition of a book will need its own ISBN. Publishers should apply for ISBNs from the ISBN agency where they are based and not to the country of the language of the book.

• Assigning ISBNs to multi-format/multi-volume works 

An ISBN must be allocated to the whole set of volumes of a multi-volume work; also, if the individual volumes of the set are sold separately, each volume must have its own ISBN. Even when each volume is not sold separately, the allocation of an ISBN to each volume is advisable. It facilitates the handling of returns (damaged volumes) and eliminates the possibility of confusion over specific publications. Each volume should list all ISBNs.

Similar rules apply to kits (e.g. a CD-ROM with accompanying booklet). If any of the parts are available separately, then each part that qualifies for ISBN assignment should be given a separate ISBN, in addition to the ISBN for the kit as a whole.

•  Identifying series 

The series may receive an ISSN (provided it is envisaged as continuing indefinitely), while the individual items should receive ISBNs. ISSN is a separate international standard and the International ISSN Centre is the registration authority for that.

• Assigning ISBNs to joint publications 

In the case of a joint publication, both publishers are entitled to have an ISBN on the book. It should be made clear which number identifies which publisher. However, if only one publisher is to hold stock and distribute the publication, then it is recommended that the ISBN of the publisher who is responsible for distribution appears in bar-coded form on the back cover of the book.

• “Out of print” editions 

Publishers assign “out of print” status when they no longer have any copies of a particular book and they have decided they will not reprint it again. An ISBN identifies a given title and its edition and binding for all time. Although a book may be out of print, it will still exist in some shops, and will certainly still exist in libraries. The ISBN will continue to identify the out of print edition and should not be reassigned to different publications.

• Assigning ISBN to individual chapters or other parts of a book that are made available separately 

If you are making chapters or other parts of a book separately available through the normal supply chain and want to have them listed in trade databases then you should regard them as individual publications and assign ISBNs to them. If they will only be available through a single source, such as the publisher’s website, then proprietary internal identifiers will be adequate.

When to assign a new ISBN 

• A revised edition of an existing book 

A (substantial) change of text requires a new ISBN, and if revisions have been made then the reverse of the title page should state that the book is a revised edition, and the new ISBN should be printed there.

• A new language edition of an existing book

Each different language edition of a book needs its own ISBN.

• A change of format

Different formats need different ISBNs in order, for example, that a customer who wants to buy a book in hardback rather than paperback can be confident that they will receive the correct format. Different formats of digital publications (e.g. pdf, html) also need separate ISBNs. 

• A change of title

Even if the content of the book is the same, because a change in title is such a substantial change it will require a new ISBN to identify it.

• A change of publisher

The ISBN identifies not only the particular publication but its publisher. If there is a change of publisher, then the new publisher must assign one of their own ISBNs to the new publication.

• A change in usage constraints

Usage constraints are used to set the limit(s) of what a user can do with a particular digital monographic publication, for example whether it is possible to print a certain percentage of the pages, whether it is possible to lend the book and whether it is possible to enable text to speech functions. Usage constraints for a digital publication are usually set within the DRM software.. If the same content is available separately with different sets of usage constraints then each of these sets will constitute a separate monographic publication.

 When to keep the same ISBN 

•  A change in price

A change in price does not require a new ISBN.

•  A reprint

The original ISBN must be retained, provided the publisher remains the same and there are no changes to text or binding.

•  Marketing or promotional changes

No, a new ISBN cannot be issued solely for marketing or promotional reasons. A new ISBN can only be issued where there are changes of text, format or binding which would justify this.