What Is ISBN? Structure and How to Generate an ISBN Code

Have you ever noticed a long sequence of numbers on the cover of a book and wondered what it’s for? That’s the ISBN — the International Standard Book Number — a unique “identity card” that distinguishes each book worldwide. But what exactly is an ISBN, why is it essential, and how is it structured?

In this article, iCheckQR will guide you through everything you need to know — from the definition, purpose, and components of an ISBN to how to generate a valid code — especially useful for authors, publishers, or anyone interested in professional book publishing.

1. What Is ISBN?

Definition

ISBN stands for International Standard Book Number, a unique identifier assigned to each book. It helps distinguish one title or edition from another across the globe.

Each ISBN is unique to a specific version and format of a book — for example, a paperback, hardcover, and eBook version of the same title will each have a different ISBN.

Historical Background

The ISBN system originated in the UK in 1966 under the name Standard Book Numbering (SBN), proposed by the bookstore W.H. Smith to better manage book inventory.

In 1970, it was standardized internationally by the International Organization for Standardization (ISO) under the code ISO 2108.

Originally comprising 10 digits, the system was expanded to 13 digits in 2007 to align with the EAN (European Article Number) barcode system, making global search, inventory, and distribution easier.

Today, ISBNs are managed by the International ISBN Agency based in London, with national ISBN agencies in each country or region handling code assignment.

2. ISBN Structure

A modern ISBN has 13 digits, divided into 5 parts, each with a specific role to identify the book. These elements are typically separated by hyphens (-):

First: Prefix Element – 978 or 979

These are the first three digits in an ISBN-13 code, typically 978 or 979.

This prefix aligns the ISBN system with the EAN-13 barcode standard, enabling compatibility for commercial use and global barcode scanning.

• Currently, 978 remains the most widely used prefix. 

• 979 is used when all 978 codes have been assigned or for special categories (e.g., printed music ISBNs).

Example: 978-604-… or 979-10-…

Second: Registration Group Element – Identifies the Language or Country Region

This segment varies in length (from 1 to 5 digits) and identifies the country or shared language area of the publication.

Examples:

• 0 or 1: English-speaking countries (UK, USA, Australia, Canada…)

• 2: France

• 3: Germany

• 604: Vietnam

• 7: China

• 978-604 indicates a book published in Vietnam.

Third: Registrant Element – Identifies the Publisher

• The length of this element depends on the size of the publisher.

• Each registrant code represents a specific publisher within the designated language region.

• Larger publishers are assigned shorter codes to allow for more title identifiers.

Example: 978-604-55 → the publisher is identified by the code 55.

Fourth: Publication Element – Identifies the Specific Edition

• This part distinguishes between different editions, formats, or versions of a particular work.

• For instance, a paperback and a hardcover edition of the same book will have different publication codes.

Example: 978-604-55-1234 → 1234 is the publication code for a specific edition.

Fifth: Check Digit – Ensures Accuracy

This is the final digit (13th) in the ISBN-13 and is calculated using a specific formula to detect input errors.

Calculation method:

• Multiply the digits in odd-numbered positions (1st, 3rd, 5th…) by 1

• Multiply the digits in even-numbered positions (2nd, 4th, 6th…) by 3

• Add all the results together

• Divide the total by 10; the remainder is R

• Check digit = 10 – R (if R = 0, then the check digit is 0)

Example: ISBN: 978-604-55-1234-9
→ 9 is the correct check digit if the calculation satisfies the formula.

3. Importance and Benefits of ISBN

ISBN is more than a string of numbers — it's a global identification system essential to the publishing process. Assigning an ISBN provides multiple benefits across the publishing value chain:

Efficient Management and Distribution Across the Supply Chain

• ISBN simplifies the processes of inventory management, book ordering, and distribution — from publishers to bookstores, libraries, and readers.

• In the global retail and publishing systems, ISBN acts as a mandatory standard identifier that allows books to be listed on platforms such as Amazon, Google Books, e-commerce sites, and library systems.

Without an ISBN, many platforms will not accept books for publication or sale.

Easy Lookup and Discovery

• An ISBN enables quick and accurate retrieval of a book’s information — including title, author, publisher, publication year, and format.

• With an ISBN, users can find the exact edition they are looking for, avoiding confusion between versions of books with the same title.

Simply entering the ISBN on Google, WorldCat, or digital library databases will return the corresponding book details.

Protection of Intellectual Property Rights

• An ISBN serves as the legal identity of a publication, helping to protect the rights of authors and publishers in cases of copyright disputes.

• Possessing an ISBN is also strong evidence of a publisher’s legitimate right to publish and distribute the work.

Statistical Tracking and Trend Analysis

• The global ISBN system provides statistical data on the number of books published, genres, and consumer trends.

• Organizations such as UNESCO, publishing associations, libraries, and research institutes rely on ISBN data to assess the current state and development trends of the publishing industry.

4. ISBN Registration Process in Vietnam

Official Governing Authority

In Vietnam, the sole authority responsible for managing and issuing ISBN codes is:

• The National Library Information Center of Vietnam

• Under the management of the Department of Publishing, Printing and Distribution – Ministry of Information and Communications.

ISBN Registration Process

Step 1: Prepare the application documents, which include:

• A copy of the publishing license (for organizations)

• Detailed information about the publication requiring an ISBN (book title, author, publisher, number of pages, dimensions, etc.)

• A sample book cover or a content description

Step 2: Submit the application:

• In person at the National Library headquarters (Hanoi)

• Or via email/online portal (if available)

Step 3: Review and issuance:

• If the application is valid, the authority will issue an ISBN within 3–5 business days

• Once issued, the ISBN must be clearly printed on the book cover and the publication information page (usually the copyright page)

Requirements and Conditions for ISBN Issuance

• Only licensed publishers or individuals/entities collaborating with a licensed publisher are eligible to apply for an ISBN

• Each ISBN is unique and can only be used for one specific publication (no reuse allowed)

• ISBNs will not be issued for:

• Internal documents

• Materials not intended for public release

• Items that are not classified as books

Note: Independent authors who wish to publish and obtain an ISBN must go through a licensed publisher; they cannot apply for an ISBN directly.

5. How to Search for a Book Using an ISBN

The ISBN is not only a tool for publication management but also an incredibly convenient resource that allows readers and organizations to accurately look up information about a specific publication.

Using Popular Websites and Databases

You can enter the ISBN (either 10 or 13 digits) into the search bar on the following reputable platforms:

How to Use: Simply enter the ISBN into the search bar on any of the websites mentioned above → and you’ll see information such as the book title, author, publisher, publication year, and book format.

Mobile Applications That Support ISBN Scanning

Smartphone apps allow you to scan ISBN codes directly from the book cover — offering a fast and convenient way to access book information:

Note: These applications typically use the camera to detect the ISBN-13 barcode (EAN-13), allowing book information to be retrieved in just a few seconds.

Example: Looking Up a Book Using an ISBN

Example: ISBN: 978-0-06-231609-7

Enter it on Amazon or Google Books → the result will display:

• Title: The Alchemist

• Author: Paulo Coelho

• Publisher: HarperOne

• Year of Publication: 2014

• Format: Paperback

You will be able to view the book’s description, reader reviews, and options to purchase or preview the content.

6. Notes on Using and Managing ISBNs

Use for the Correct Purpose

Each ISBN must be used for one unique publication only.

If a book has multiple versions, each format requires its own ISBN:

• Paperback → 1 ISBN

• Hardcover → a different ISBN

• eBook → a separate ISBN

• Audiobook → also requires its own ISBN (if officially published)

Assigning the correct ISBN for each format ensures transparent publishing management and prevents confusion during distribution.

Avoid Confusion with Other Identifiers

Many people often confuse ISBN with ISSN or DOI, although these codes are used for different types of materials. Below is a simple comparison table:

Examples:

• A textbook → ISBN

• A scientific paper → DOI

• A monthly magazine → ISSN

7. Frequently Asked Questions (FAQs)

Is an ISBN Mandatory?

Not entirely. ISBNs are not legally required, but they are practically essential if you want to:

• Publish a book through an official publisher

• Distribute your book through bookstores, e-commerce platforms, libraries, or internationally

Cases where ISBN registration is not required:

• Internally printed books used within an organization or company

• Complimentary or gift books not intended for commercial sale

• Materials not released to the public (e.g., internal theses, newsletters)

Can an ISBN Be Reused?

No. Each ISBN is unique and cannot be reused.

Even if a book is discontinued, withdrawn, or no longer printed, its ISBN remains permanently associated with that specific publication in the system.

Reusing an old ISBN for a new book is a serious violation and causes data discrepancies in libraries, bookstores, and global publishing platforms.

Does an ISBN Cost Money?

• In Vietnam: The official issuing authority is the National Library of Vietnam, which does not charge a fee for ISBN registration through a licensed publisher.

Individual authors must work with a licensed publisher to obtain an ISBN.

• In other countries:

• United States (via Bowker): Starting at $125 per ISBN or around $295 for a pack of 10

• United Kingdom (via Nielsen): Varies by package, but generally cheaper than in the US

• Canada: Free (government-issued)

• Australia: Fees apply

Does an ISBN Expire?

No. ISBNs do not have an expiration date. Once issued, the ISBN is permanently tied to that edition of the publication.

However, if significant changes are made to the publication, such as:

• Change of publisher

• Change of format (e.g., paperback → eBook)

• Addition of content or major revisions → new version

→ A new ISBN must be issued for the updated version.

Difference between ISBN and Barcode?

The ISBN serves as the input data for generating an EAN-13 barcode.

Publishers or printing houses can use software or online tools to convert an ISBN into a barcode.

8. Common Mistakes in ISBN Registration

Incorrect Publisher Information During Registration

In many cases, incorrect publisher names, codes, or addresses are submitted, or there is no valid publishing contract in place.

Make sure to verify all information through:

• The publisher’s official website

• The publisher’s operating license

• The National Library

Note: Independent authors must sign a publishing agreement with a licensed publisher in order to be eligible for ISBN issuance.

Incorrect Use of ISBN-10 and ISBN-13 Formats

• ISBN-10 was used prior to 2007 (10 digits)

• ISBN-13 is now the global standard (13 digits, beginning with 978 or 979)

Using the wrong format, or reusing an ISBN-10 without properly converting it to ISBN-13, can cause system errors or data mismatches.

Simple Conversion Table:

How to Calculate the ISBN-13 Check Digit:

• Apply the following rule: Multiply digits in odd positions by 1 and even positions by 3 → sum all values → divide the total by 10 → take the remainder → check digit = 10 minus the remainder.

• If the remainder is 0, then the check digit is also 0.

Failure to Update When Ownership Changes

• When the ownership rights of a book are transferred to another publisher or entity, continuing to use the old ISBN without updating it can disrupt the management system.

• If there are significant changes in ownership, copyright, or publishing rights, it is recommended to register a new ISBN to ensure legal validity and transparency.

Conclusion

ISBN is a globally standardized identifier that helps books reach the market more easily, be integrated into global distribution systems, support effective management, and protect the legal rights of both authors and publishers.

Using ISBNs correctly, understanding their purpose, and avoiding common mistakes will significantly enhance professionalism, transparency, and efficiency in all publishing and book distribution activities — whether you are a self-published author, a publishing house, or a professional in the book industry.