The ISBN code – International Standard Book Number – it’s a 13 digit number standardized internationally that identifies one specific book, paper or digital: even an ebook publication has a different code than the same paper publication, since they are different book types. ISBNs are sold to publishing houses by designated bodies, in Italy specifically by the Italian Publishers Association. THE‘ISBN is required to sell any type of book, and also those who publish in self-publishing must therefore purchase a code; however, it is not mandatory to enter the code if you sell a title only privately, if the text never enters the sales circuit in bookshops or online channels.
What is the ISBN code for and how is the string formed
The ISBN code uniquely and internationally identifies a specific edition of a book. It provides information on title, author and edition, and is essential for the cataloguing, distribution and sale of the book (including e-books) in bookstores, libraries and online stores.
The ISBN code consists of five subgroups of numberseach referring to an area that allows you to recognize that specific book among all the others in the world. The 13 figures are divided into 5 areas:
- Prefix that identifies that the object in question is a book. It is a 3-digit prefix adopted internationally according to the GS1 system, a global standard used to identify products, places and services.
- Prefix oflinguistic areawhich therefore identifies what language the book is written in. It is attributed by the International ISBN Agency and can have from 1 to 5 digits. The Italian linguistic area is coded by the numbers 88 and 12.
- Prefix publisheris the code that identifies the single publishing house or publishing brand within a specific linguistic group. It can have 2 to 6 digits: if the publisher publishes many titles, the prefix will be shorter because there will be more numbers available to identify individual books in the next section of the ISBN; if it publishes fewer titles, the prefix will be longer.
- Code title identifierwhich will have as many digits as left available from the previous sections, specifically from the publisher prefix. The shorter the publisher prefix, the greater the number of title identifiers available, and therefore ISBN availability
- The control numberwhich varies from 0 to 9, inserted as a guarantee against possible transcription errors in the code.
How to get an ISBN for a book: who can buy it and how much it costs
In Italy, ISBN codes are assigned by the Italian Publishers Association: each publishing house purchases the necessary codes and uses them until they run out. Publishers are organized into groups based on the publisher prefix, i.e. the number of titles published or planned, and each group has dedicated rates. For example, 10,000 ISBN codes for group B publishers, with a 3-digit prefix, cost €4,500 plus VAT.
Since ISBN codes are limited, the publisher must choose and purchase the prefix by anticipating how many codes it will use over the years. If a publisher runs out of available ISBNs for the number of digits of the title, it will have to acquire a new prefix and will therefore be recognizable with different codes.
Also occasional publications and self publisher they can have their own ISBN code, which can be purchased individually or in small groups: an ISBN code costs €60 + VAT, 5 codes €200 plus VAT.
Ebooks, out-of-print books and reprints: when does the code stay the same and when does it change?
When the same title comes out both in paper version and ebookmust have two different ISBNs: the ebook must also have a different ISBN for each format in which you choose to release it, for example .lit, .pdf, .html, .pdb, etc. This is done so that you can distinguish with certainty which digital format you are purchasing, given that not all formats are readable on all media. When a book comes reprinted – that is, when new copies are added to the initial print run – the ISBN code remains the same.
The ISBN changes when one is put on the market new edition which has substantial changes or innovations compared to the previous one: for example, if the same publisher publishes an illustrated edition of a book that it has already published, and the final result is therefore a completely different book, despite having the same title it will have a different ISBN.
Another case where the ISBN must be different is when change the format: for example, if a large format edition becomes a paperback book, the code also changes, again to ensure that the ISBN identifies that book with specificity. When a book comes withdrawn from the market – it is therefore said that it goes out of print – the ISBN still remains assigned to that title because, potentially, the book can still be sold.









