International Standard Book Number (ISBN)

The International Standard Book Number (ISBN) is a unique international identifier for books or other monographic publications, approved as an ISO standard (ISO 2108: 2005), which facilitates its circulation in the publishing market.

In other words, it is a standardized code that uniquely identifies the works intended for sale, which facilitates commercial transactions between customers, libraries, publishers and other agents involved in the commercial circuit of the book.


From January 1 of 2007, the ISBN digit has a numeric structure consisting of 13 digits (instead of the previous 10 digits), grouped into the following blocks:

Bloc Example
Prefix identifier for the book sector 978
Identifier of the national, geographic or linguistic group of publishers 97884-
Editorial prefix that identifies the specific editorial of each group 84369-
Title number that identifies the title or edition of a work published by a specific publisher or author / publisher 84-369-3532-

Control digit that guarantees the correct use of the entire system


The structure of 13 figures was implanted by the exhaustion in some parts of the world of the possible numerical combinations (as a result of the increasing number of publishers and existing publications). When the ISBN prefixed with 978 is depleted, the 979 prefix will also be entered.

In this way, the ISBN becomes identical to the EAN 13 "Bookland" code that appears printed in the bar code of the back cover of the books.

In case you need to know an ISBN of 13 digits, from the corresponding 10 digits, you can use the converter

The ISBN facilitates the circulation and commercial operations of the monographs in the publishing market, since it allows to identify the title and the edition of a work published by a certain publisher or author / editor, as well as to use the Database of books published in Spain or the ISBN database (international scope) to locate it.

In relation to the request of an ISBN and taking into account its purpose:

  • If a work does not have any commercial purpose, it is not necessary to request the ISBN because this identifier only serves to facilitate commercial transactions.
  • As established by User manual ISBN, the editors of the documents (or the authors themselves responsible for editing) must request the ISBN before their final impression so that the document clearly appears.
  • In Spain, the ISBN is assigned by l'Agency ISBN, an entity managed by the Federation of Publishers 'Guilds of Spain, according to an agreement signed with the Ministry of Culture, the Department of Culture and the Media of the Generalitat de Catalunya and the Federation of Publishers' Guilds of Spain.
  • As it explains the same ISBN agency, the ISBN should not be confused with an indicator of quality or scientific excellence. This numerical code is only an administrative procedure that in no case guarantees the scientific or technical quality of the document to which it is granted. Therefore, all those documents (doctoral theses, papers, teaching materials, research reports, etc.) that have not been published with the aim of being intended for sale do not require an ISBN.
  • In relation to doctoral theses, it should be borne in mind that in the evaluation models of ANECA's teacher accreditation programs, the value of the theses weighs the same regardless of their means of publication. Therefore, it is not a requirement that editions have ISBNs (currently, AQU faculty evaluation committees are evaluating the application of the same measure).

ISBN codes with prefixes assigned to the UPC They are managed directly by the Digital Polytechnic Initiative (IDP), for those works that you edit and / or distribute as a further task of the editing process.

The person in charge of managing the ISBN codes is:

Ana Latorre:

Authors or authors / publishers may request an author's ISBN as per the table below:

Non-commercial works

Authors who need to obtain an ISBN for non-commercial works to meet the requirement required by some academic evaluation agencies (merit contests) may request it according to procedure and rates established by the ISBN Agency.

Realty works People or institutions that are not publishers and publish a work for commercial purposes, can request a ISBN of author / editor at the Agency, according to procedure and rates established

Last update: 13 / 05 / 2022