Byte Experts: Eleanor Pigg Explains ISBNs

Posted by Monica Cardenas on 23 February 2023, in Byte Experts, News

1. Why do we need ISBNs?
Most of our telephone conversations at the UK & Ireland ISBN Agency start with “I’ve written
this book… now what do I do?” My first question to them is “Do you have an ISBN” to which
the answer is usually “What’s an ISBN? Why do I need one?”

There are three important questions a new publisher or self-publishing author should
consider when deciding whether they need an ISBN:
Do you want your books to be discovered online and in bookshops?
Do you want to sell books as the ordering and distribution of books is generally
executed by the ISBN?
Do you want to analyse those sales?

If the answer to any of these questions is yes, you need an ISBN.

The ISBN is a unique internationally recognised identifier for monographic publications;
assigning a number replaces the handling of long bibliographic descriptive records, thereby
saving time and staff costs and reducing copying errors.

As a self-published author, by obtaining an ISBN you will be able to take the necessary
steps to ensure that your book is widely known and maximise its sales potential. Correct use of the ISBN allows different product forms and editions of a book, whether printed or digital, to be clearly differentiated, ensuring that customers receive the version that they require.

The ISBN facilitates compilation and updating of book-trade directories and bibliographic
databases, such as catalogues of books-in-print. Information on available books can be
found easily.

Ordering and distribution of books is generally executed by the ISBN; this is a fast and
efficient method. The ISBN is machine-readable in the form of a 13-digit EAN-13 bar code. This is fast and avoids mistakes. The ISBN is required for the running of electronic point-of-sale systems in bookshops. The majority of publisher’s and supply chain systems are based on the ISBN.

The accumulation of sales data is done by the ISBN. This enables the varying successes of
different product forms and editions of publications to be monitored, as well as enabling
comparisons between different subject areas and even different publishing houses.

The national lending right in some countries is based on the ISBN. Such schemes enable
authors and illustrators to receive payments proportionate to the number of times that their
books are lent out by public libraries.

2. Who came up with the ISBN and why?
In 1967, the Whitaker company generated the first SBN. The SBN or Standard Book Number was born two years earlier, in 1965, when WHSmith challenged a Professor of Statistics at the London School of Economics to come up with an algorithm to help them track books. The ISBN has been integral to the book trade ever since. It became the International Standard Book Number in 1970.

Whitaker, which subsequently became Nielsen BookData, has had the privilege of running
the UK and Ireland ISBN Agency since 1967. Today the UK & Ireland Agency assigns ISBNs
to publishers based anywhere in the British Isles and Ireland and is one of the largest
Agencies in terms of ISBN prefixes allocated.

Each country has a National ISBN Agency and is only permitted to supply ISBNs to those
publishing within their territories, we are therefore only allowed to supply ISBNs to publishers
based in, and publishing from the UK & Ireland and 14 British Overseas Territories, including
such exotic places as Tristan da Cunha, Montserrat, Pitcairn and Turks and Caicos.

3. How do they differ from barcodes in other retailing environments?
The barcode on a book is simply an electronic, scannable version of the ISBN. All it
contains is the ISBN, no other data such as price. When you register your book with Nielsen
BookData, you supply information such as title, format, price, author etc. Nielsen BookData
will then send this information to the trade – booksellers, libraries, distributors and their
international data customers. When you subsequently go into a bookshop and the barcode is
scanned, that is when all the necessary data will appear. If the book isn’t registered, booksellers won’t know it exists and the scanned barcode will not bring up any information.

The ISBN is a derivation of the EAN, which is used by pretty much all retailers, regardless of
environment, however an ISBN barcode is specifically derived from the ISBN. If you look at
a barcode on a book you will see the ISBN sitting on top of the barcode graphic and the
resulting EAN sitting below the barcode graphic. You will see that the number is exactly the
same except maybe for the spacing of the numbers. For more specific information about EANs, visit GS1UK who are the regulatory trade body
for EANs in the UK.

4. What are the constituent parts of an ISBN?
ISBNs are calculated using a specific mathematical formula and include a check digit to
validate the number. ISBNs don’t expire, however once used, they cannot be reused simply because a previous title is no longer in print. That ISBN identifies a single title and format of a book for life! The ISBN is broken into five elements.

  • Bookland Prefix: this shows that the identifier being used is for a book – it is “from”
  • Registration Group: identifies a country, area or language area where the publisher is
    based and the ISBN is assigned
  • Registrant (Publisher) identifier: identifies a particular publisher and usually indicates
    the exact identity of the publishing house and its address
  • Title Identifier: identifies a specific edition of a publication of a specific publisher
  • Check Digit: validates the full number


Take the Writers and Artists Yearbook 2020 as an example.
Published by an imprint or subsidiary of Bloomsbury, called Bloomsbury Information. An
imprint is defined as a wholly owned subsidiary of a publisher. Imprints are generally used to
publish different genres. When asked for your ‘Imprint name’, generally what they really
mean is what is your ‘Publisher’ name.
The ISBN itself: 978-1-4729-4751-2 
This ISBN comes from an allocation assigned to Bloomsbury back in 2012 and contains
10,000 ISBNs, and this prefix has been shared with other Bloomsbury imprints, so they can
utilise the allocation as well.
978 identifies that the product is a book
1 – Is the Area Code if you like for an Anglophone area, meaning that it belongs to a
publisher based in either the UK, Australia, New Zealand, Canada, South Africa, or the USA.
In this case it is an allocation assigned to the UK by the International ISBN Agency, who
assigns all allocations to all Agencies around the world.
4729 - The next four digits is the Publisher number for Bloomsbury - together with the 1, this
makes up the publisher prefix.
4751 - The next four digits are the Title number – this is where the ISBN used comes in the
allocation of ISBNs assigned to Bloomsbury. This is the only sequential part of the ISBN.
2 - And the final digit is completely random and seemingly makes no sense, but this is the
Check Digit, the result of the algorithm. This validates the whole number

We also supply single ISBNs, while they identify a title and format of a book, they are not
unique to the publisher as a larger allocation would be. We are only able to supply single
ISBNs because we have used a much larger allocation of 10,000, meaning that we can offer
customers who only really need one number the option of the single rather than having to
purchase a larger allocation.

5. Are they the same in every book market globally? 
ISBNs are geo-specific. Irrespective of your nationality, citizenship, what language the book
is written in, where the book is printed or for sale, it is only the country in which you are
based and are publishing from that determines where you acquire an ISBN.  Even if, for
example, you are English but based in and publishing from Spain, then the ISBN should be
acquired from the Spanish ISBN Agency. If you move to another country, you will need to
acquire ISBNs from that country’s Agency, you cannot use the ISBNs acquired from the UK
& Ireland Agency in another country of publication.

Each country has a National ISBN Agency and is only permitted to supply ISBNs to those
publishing within their territories. For further information please visit the International ISBN
Agency website

An ISBN is recognised internationally, which means that you can sell your book in whichever
country you wish. If you are a non-UK-based publisher, you can supply the title information
to Nielsen BookData regardless of the place of publication, however, it must be identified
with an ISBN from your National ISBN Agency.

6. What is the process of allocating an ISBN to a new book?
First you need to acquire your ISBNs! If you are based in the UK or Ireland or any of the
territories we cover and want to publish your book you should contact the UK & Ireland ISBN
Agency. Our Online Store ( allows you to purchase ISBNs immediately
24/7. It’s the fastest and most popular way to purchase either a single ISBN or larger
allocations, up to a block of 1,000, and includes details about other Nielsen BookData

We also offer a manual application, found on our Nielsen BookData website. There are
many reasons customers have to use this form, such as different payment preferences, an
aversion to online forms in general or they need allocations larger than 1,000. The largest of
which is 100,000.

Once you have purchased ISBNs you can then register with Nielsen BookData’s free online
service Title Editor. Title Editor is a way to send new title information and keep existing titles
up-to-date. You can register to use the service here

If you have any problems registering your books you can contact the Publisher Help
Desk:, or telephone 01483 712450. Nielsen BookData adds basic details for titles free of charge, if you would like to add more enriched information such as descriptions, table of contents, author biographies, etc please email:

You should send a copy of each title you publish to the Legal Deposit Office at the British
Library.  Further details are at

Once a record is added to the database the details are sent to data customers including
Waterstones,, and numerous other websites, booksellers and distributors.
Please allow 3-5 days for your title to be fully listed on Nielsen BookData’s database and

7. Do you have any ISBN stories or anecdotes?
We interact with many, many different people from all walks of life, Dukes, Military
Regiments, Museums, Her Majesty’s various Government Ministries, an Engineer of the
Harrier Jump Jet, Rugby Internationals, captured World War II Tommies, Psychics who
‘channel’ their books, a wonderful gentleman from Alnwick whose lifelong quest was to save
the Red Squirrel – all walks of life. In one lively case a journalist and BBC broadcaster who
had interviewed people such as Noel Coward, Albert Finney, Harold Pinter, Peter Hall and
many more! He was an amazing, fascinating man and at 80 something he was also still
game to go zip-lining in Costa Rica! We interact with lots of lovely, interesting people, there
is no one kind of author, that’s for sure.

Eleanor Pigg is the Manager of the UK & Ireland ISBN Agency, advising publishers of all
sizes about the use of ISBNs and best practice. She also manages the SAN Agency
allocating SAN identifiers to the book industry. You can follow the ISBN Agency on
Instagram @ukisbnagency for tips and advice.

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