How to Buy an ISBN in the UK: Nielsen, Resellers or KDP's Free ISBN?

An ISBN costs anywhere from £0 to about £93. The difference isn't the number. It's whose name sits next to it.

Key takeaways#

• UK authors get ISBNs from Nielsen (the national agency), from a reseller, or as a free Amazon KDP ISBN for print that stays on Amazon.
• A Kindle ebook does not need an ISBN (Amazon uses an ASIN). Each print or ebook format you sell outside Amazon's free option needs its own ISBN.
• Nielsen lists you (or your imprint) as publisher of record. A reseller usually lists the reseller for database purposes. KDP's free ISBN shows as Independently published and cannot travel to other platforms.
• Checked on 2 October 2026, Nielsen's store prices (VAT-inclusive) are £93 for one ISBN and £174 for a block of 10. Reseller packs are cheaper per number but change who appears on the record.
• Choose by where you will sell and whether you want your own imprint — not by habit or fear of any one option.

Do you actually need an ISBN?#

For a Kindle ebook, no. Amazon identifies the title with an ASIN. An ASIN is not an ISBN, and you should not treat them as interchangeable. See Do I Need an ISBN for Kindle? if that is your only format for now.

For a paperback or hardback, you need an ISBN if you want bookshops, libraries and trade databases to order the right edition. Amazon KDP will issue a free ISBN for a paperback that stays on Amazon. If you want the same edition on IngramSpark, Draft2Digital print or another printer, you need an ISBN you control.

Each format needs its own ISBN. Paperback, hardback and ebook are separate products. A new edition with substantial changes usually needs a new ISBN too. For the basics, start with ISBNs explained.

Option 1: Buy direct from Nielsen (the UK ISBN agency)#

Nielsen Book is the UK ISBN agency. If you are based in the UK, Ireland or a British Overseas Territory, you buy from the Nielsen UK ISBN Store. You register as a publisher — that can be your own name or an imprint you invent — then buy a single ISBN or a prefix block.

Prices checked on 2 October 2026 on nielsenisbnstore.com (all inclusive of UK VAT):

• 1 Single ISBN: £93.00
• Prefix for 10 ISBNs: £174.00 (£17.40 each)
• Prefix for 100 ISBNs: £387.00
• Prefix for 1000 ISBNs: £994.00

Unused numbers remain valid indefinitely. After purchase you assign metadata (title, contributor, format, price) so trade systems can list the book correctly.

Best for: authors building a small press or imprint, or anyone who wants their own publisher name on the bibliographic record for every format.

Option 2: Buy from a reseller (like HMD)#

Resellers buy blocks from the national agency and sell individual numbers to authors. You get a working ISBN-13 faster and usually pay less for a single number than Nielsen's single price — with a clear trade-off on who is listed as publisher of record.

HMD ISBN packs (from our ISBN service; VAT is added for UK customers at checkout; prices are one-time with no recurring fee):

• Single: £27.99 ($34.99)
• 3-Pack: £97.99 ($124.99)
• 10-Pack: £197.99 ($249.99)
• 100-Pack: £997.99 ($1,249.99)

What you typically get with a reseller pack: the number emailed quickly, a Books in Print–style listing, barcode files, and a number that works on platforms that accept ISBN-13 (including KDP, IngramSpark and Draft2Digital).

Honest disclosure: HMD is a reseller, not the national agency. HMD Publishing Ltd is listed as publisher of record on industry databases for administrative purposes. You keep full copyright, creative control and 100% of royalties. If you want your own imprint on the record, buy direct from Nielsen instead. That is the right choice for many imprint-builders, and we say so on purpose.

Option 3: KDP's free ISBN#

Amazon KDP can assign a free ISBN to a paperback (and, where offered, hardcover) at no cash cost. The publisher line shows as Independently published. That ISBN is for use on Amazon only — you cannot take the same free KDP ISBN to IngramSpark or another distributor.

Best for: a first Amazon-only paperback test, or a project where you are not yet ready to buy numbers. Fine as a starting point. Not fine if you already know you will go wide with the same print edition.

Side-by-side comparison#

Which should you choose? Four common situations#

One paperback on Amazon only. A free KDP ISBN is fine. You can buy your own later for a new edition or a wide release.

Paperback + hardback + ebook, going wide. Plan three ISBNs (ebook only needs one if you use ISBN for wide ebook stores; Kindle can still use an ASIN). A 3-pack or Nielsen's 10-block both work. Prefer Nielsen if the imprint name matters to you.

Building a small press or imprint. Buy from Nielsen so your publisher name is on the record from day one.

Series author with several formats. A 10-pack (Nielsen or reseller) is usually better value than repeating singles. Series maths eats numbers quickly.

If you are mapping the whole UK path — edit, files, KDP, IngramSpark, legal deposit — see How to Self-Publish a Book in the UK.

After you buy: assign it and get a barcode#

1. 1Put the ISBN on the copyright page and in every platform's metadata fields exactly the same way (digits only or with hyphens — be consistent with what the store asks for).
2. 2Generate a print-ready barcode for the back cover with the free ISBN barcode generator (UK).
3. 3Confirm the number resolves with the free ISBN lookup (UK).
4. 4Do not reuse a KDP free ISBN on IngramSpark. If you start free on Amazon and later go wide, assign a new owned ISBN to the wide edition (and treat metadata carefully so stores do not clash).

An ISBN does not give you copyright. In the UK, copyright in your original work arises automatically. For the page wording and moral rights notes, see How to Copyright a Book and the free copyright page generator (UK).

What the "publisher of record" line actually means#

Book trade databases need a publisher field. That field is not the same thing as owning copyright, and it is not a claim on your royalties.

• Your imprint (Nielsen): shops and libraries see the name you registered. Useful if you brand a small press or want every title under one house name.
• Reseller listing: the reseller's company name appears in that database field. Your contract and copyright page still show you as the rights holder. Readers on Amazon mainly see your author name and the book title.
• Independently published (KDP free): Amazon's label for titles using their free ISBN. Clear and honest for an Amazon-only test; limited if you later want trade distribution for that same ISBN.

None of these options transfers your copyright. None of them should be confused with traditional publishing contracts.

Common mistakes that waste an ISBN#

• Buying one ISBN and putting it on paperback and ebook. Those are two products.
• Using a free KDP ISBN on an IngramSpark title setup. Platforms will reject or create a conflict.
• Finalising a barcode price add-on, then changing the list price without updating the cover file.
• Waiting until upload day to buy from Nielsen if you need an imprint — allow time for the agency account and title assignment.
• Assuming an ISBN equals legal deposit or PLR registration. Those are separate UK steps after publication (covered in our UK self-publishing guide).

For bookshop-oriented print distribution after you own an ISBN, read how to get your self-published book into bookshops and keep free ISBN barcode generator guide handy when the cover is in design.

Frequently asked questions#

Next step#

If you want your own imprint on the record, go to Nielsen and buy the block that matches your catalogue. If you want a portable ISBN today without running an imprint, you can buy ISBN packs from HMD — emailed quickly, with barcode files included. For wider setup help (KDP plus trade distribution), see Publishing and Distribution.