ISBN Registration Groups: A Complete Guide to Country and Language Codes

Have you ever wondered what the numbers after the 978 or 979 prefix in an ISBN mean? Those digits are not random. They tell the world exactly where your book publisher is registered.

This is the registration group element, and understanding it is essential for anyone serious about global book distribution. It is the digital fingerprint that connects every ISBN to a specific country, region, or language area.

What is an ISBN Registration Group?

An ISBN registration group is a set of one to five digits that identifies the country, geographic region, or language area where a book publisher is registered. It is the second segment of every 13-digit ISBN.

For example, in the ISBN 978-0-13-468599-1:

978 is the prefix (Bookland)
0 is the registration group (English-speaking countries)
13 is the registrant (publisher)
468599 is the publication element
1 is the check digit

The length of the registration group varies. Countries with high publishing output get shorter codes. Countries with lower output get longer ones. This smart allocation maximizes the number of unique ISBNs available worldwide.

Major Registration Groups Under 978

The original 978 prefix has been in use for decades. Here are the primary registration groups you will encounter most often:

Single-Digit Groups (High Volume)

These are assigned to the largest publishing markets:

0 or 1 – English-speaking countries (USA, UK, Australia, Canada)
2 – French-speaking countries
3 – German-speaking countries
4 – Japan
5 – Russian-speaking countries (former USSR)
7 – People’s Republic of China

Two-Digit Groups

These cover major national markets:

80 – Former Czechoslovakia (now Czech Republic and Slovakia)
81 – India
82 – Norway
83 – Poland
84 – Spain
85 – Brazil
86 – Former Yugoslavia
87 – Denmark
88 – Italy
89 – Republic of Korea
90 – Netherlands
91 – Sweden
92 – International Publishers (UNESCO, EU)
93 – India (additional range)

Longer Groups (Lower Volume)

Countries with smaller publishing industries receive longer codes (3–5 digits). For example:

99936 and 99980 – Bhutan
99959 – Luxembourg

This hierarchy ensures efficient use of the finite ISBN space.

The New 979 Registration Groups

As the 978 prefix began running out of available numbers, the International ISBN Agency introduced 979. This prefix now has its own set of registration groups:

979-8 – United States of America
979-10 – France
979-11 – Republic of Korea
979-12 – Italy
979-13 – Spain

One key difference: 979 ISBNs do not have a 10-digit equivalent. They are always 13 digits. You can learn more about this in our guide to ISBN Prefix 979 and Bookland.

The Role of National ISBN Agencies

Each registration group is managed by a national ISBN agency. These agencies are responsible for:

Issuing ISBNs to publishers in their territory
Assigning publisher codes (registrant elements)
Maintaining the Global Register of Publishers
Reporting data to the International ISBN Agency

The structure of these agencies varies by country. Some are government-funded and offer free ISBNs to citizens. Others, like Bowker in the US or Nielsen in the UK, are private companies that charge for each ISBN.

To find your local agency and compare costs, use the ISBN Agency Lookup tool. It provides details on each agency, including whether ISBNs are free or paid in that region.

Why Registration Groups Matter for Authors

Understanding registration groups has practical benefits for self-publishing authors:

1. Publisher Identification

Anyone in the book trade can look at your ISBN and instantly know which country your publisher is registered in. A book with a 978-0 or 978-1 prefix signals an English-speaking market publisher.

2. Distribution Logistics

Some distributors and retailers filter catalogs by registration group. Knowing your group can help you understand how your book appears in different regional markets.

3. Metadata Accuracy

When you hyphenate your ISBN correctly, the registration group becomes visible. This is critical for accurate cataloging and ensures your book can be traced back to its origin.

How to Find Your Registration Group

If you have an ISBN and want to identify its registration group, you can use tools that reference the official ISBN range data maintained by the International ISBN Agency.

This data is updated regularly as new groups are added or existing ranges are expanded. The hyphenation of an ISBN directly depends on this data set.

Conclusion

ISBN registration groups are the geographic backbone of the global book identification system. They connect every published book to a specific country or language area.

Whether you are a self-publishing author or a traditional publisher, knowing your registration group helps you understand your book’s place in the international book trade. It is one more piece of the puzzle in building a professional publishing identity.

If you are curious about how much ISBNs cost in your country, check the ISBN Agency Cost directory for a complete breakdown by country.