You’ve written the book. You’ve edited it, designed it, published it. Now you’re waiting for readers to find it. And they’re not.
This is one of the most frustrating experiences in independent publishing – and one of the most common. The book exists. The book is good. But somewhere between the page and the reader, something is missing.
That missing thing, more often than not, is metadata.
Metadata is everything attached to your book beyond the words inside it: your title, author name, description, subject categories, keywords, ISBN, price, and more. It is the information that tells retailers, libraries, search engines, and distribution systems what your book is, who it’s for, and where it belongs. And crucially, it is what makes your book discoverable – not just to readers browsing Amazon, but to library buyers, booksellers, and wholesalers across the UK, Europe, and beyond.
Metadata isn’t an afterthought. It is your marketing – working quietly and continuously long after any paid advertisement has expired.
What Is Book Metadata?
In plain terms, metadata is every piece of information about your book. It sits behind the scenes, flowing through digital systems – from your upload on IngramSpark to a library buyer’s catalogue, from Amazon’s search algorithm to Nielsen’s database – telling each of those systems how to classify, display, and surface your book to the right audience.
For independent authors, metadata matters even more than it does for traditionally published authors. A large publisher has a marketing and distribution team managing this work. As an independent author, you are that team. Understanding and investing in your metadata is one of the highest-value activities you can do for your book’s long-term success.
Why Metadata Is Your Most Powerful Marketing Tool
Good metadata works on multiple levels at once.
Discoverability. When a reader searches for “cosy mystery set in Scotland” or “WWII historical fiction strong female lead,” the algorithms matching their search to relevant books are reading metadata. If yours is accurate, specific, and keyword-rich, your book appears. If it isn’t, it doesn’t.
Longevity. Unlike a paid social media campaign that runs for a week, good metadata keeps working indefinitely. It is a permanent investment in your book’s visibility.
Library and retailer access. Systems like Nielsen BookData (which feeds UK retailers and libraries), IngramSpark (which reaches over 39,000 global retailers), and Gardners (the UK’s leading book wholesaler) all rely on clean, complete metadata to list and supply your book. Poor or missing metadata means your book may simply not appear in their catalogues.
A note of caution. Poor metadata doesn’t just limit visibility – it can actively harm your book. Inconsistent author names across platforms, vague subject categories, or a missing ISBN for a particular format can all create confusion in supply chains and reduce retailer confidence in stocking your title.
Understanding Subject Classification Systems
One of the most important – and most misunderstood – areas of metadata is subject classification. These are the standardised codes that tell retailers, libraries, and distributors exactly what your book is about and where it belongs. They are not the same as your keywords, and they are not optional.
There are several systems in use globally, and authors publishing across multiple markets need to understand the landscape.
BISAC (Book Industry Standards and Communications)
BISAC is the North American standard, developed and maintained by the Book Industry Study Group (BISG). It is widely used by Amazon KDP, IngramSpark, US retailers, and distributors. BISAC codes look like this: FIC022020 FICTION / Mystery & Detective / Police Procedural.
BISG recommends selecting up to three BISAC codes per title, with the most relevant listed first. The full list is freely available to browse online at no cost at bisg.org. No subscription is required to look up and select codes for your book.
THEMA
THEMA is the international standard, developed by EDItEUR, and has been the primary subject classification scheme for UK and European publishing since February 2024, formally replacing the older BIC system. It is used by Nielsen, Gardners, Waterstones, WH Smith, Blackwell’s, Kobo, and an increasing number of UK and EU retailers and library suppliers.
THEMA is designed to work alongside BISAC, not replace it. Authors publishing for both UK and US markets should use both systems. THEMA codes are structured differently — they include subject categories and qualifiers (for place, time period, language, and more), allowing for very precise classification.
The full THEMA hierarchy is freely browsable and searchable at ns.editeur.org/thema/en. No registration or subscription is required. The browser allows you to search by keyword or navigate the full category tree.
BISG also maintains a BISAC-to-THEMA mapping document, which can be a useful starting point for authors who have already chosen their BISAC codes and want to identify equivalent THEMA codes.
BIC (Book Industry Communication)
BIC was the previous UK subject classification scheme. It is now effectively obsolete – formally deprecated in February 2024 – though some legacy systems may still reference it. Authors should not spend time selecting BIC codes for new publications; THEMA is the correct UK standard going forward. You may encounter BIC codes referenced by older platforms or services, but it is simply the predecessor to THEMA and no longer the active standard.
Amazon Browse Categories
Amazon operates its own internal category system, separate from BISAC. On KDP, authors select up to two browse categories from Amazon’s own dropdown menus. These categories directly influence which bestseller lists your book appears on and which “also bought” sections surface it.
Amazon’s browse categories are not automatically derived from your BISAC codes — they are a separate selection made within KDP. However, the BISAC codes you enter on KDP do influence Amazon’s category assignment behind the scenes, so it is worth being thoughtful about both. Additional categories can sometimes be requested from KDP customer support after publication.
Think of Amazon categories as a distinct task that sits alongside – not instead of – your BISAC and THEMA selections.
The Metadata Checklist: What Every Author Needs to Get Right
Work through this checklist before you upload your book to any platform. Prepare your answers in advance; the upload process is not the right moment to make these decisions for the first time.
✔️ Title and subtitle – Exactly as it will appear on the cover and copyright page. Consistent across every platform.
✔️ Author name – Consistent spelling and format everywhere: Amazon, Nielsen, IngramSpark, your website. Variations confuse algorithms and catalogues.
✔️ ISBN – One per format (print, ebook, audiobook, hardback). Do not share ISBNs across formats or platforms.
✔️ Book description / blurb – Keyword-rich, compelling, and correctly formatted for each platform. This is both a marketing tool and a discoverability asset.
✔️ BISAC categories – Up to three, most specific first. Browse the free list at bisg.org. Required for Amazon KDP and IngramSpark; used by US retailers and distributors.
✔️ THEMA categories – The current UK and international standard. Browse the free hierarchy at ns.editeur.org/thema/en. Required for Nielsen Title Editor and UK/EU retailer and library visibility. Use alongside BISAC, not instead of it.
✔️ Amazon Browse Categories – Selected separately within KDP. Research which categories competing books in your genre use and consider whether additional categories can be requested via KDP support.
✔️ Keywords – Amazon KDP allows seven keyword fields. Use phrases readers actually search for. Avoid repeating words already in your BISAC or THEMA codes, as these are already factored into retailer algorithms.
✔️ Series information – If applicable: series title and volume number. Especially important for fiction.
✔️ Publication date – Consistent across all platforms. Nielsen recommends submitting at least five months before publication to support pre-sales activity.
✔️ Page count and format details – Including trim size for print editions.
✔️ Cover image – Correct file dimensions and resolution per platform requirements.
✔️ Territorial pricing – Including UK (GBP), US (USD), and EU (EUR) where applicable. IngramSpark allows global pricing per market.
✔️ Publisher / imprint name – Even as an independent author, registering and consistently using an imprint name adds professionalism and helps library and retailer systems recognise your output.
✔️ Audience classification – Adult / general, young adult, children’s, etc. Required by some retailers and library systems.
Common Metadata Mistakes to Avoid
- Inconsistency across platforms. Your name, title, or ISBN appearing differently on KDP versus IngramSpark versus Nielsen can cause cataloguing errors and undermine retailer confidence.
- Using only BISAC and ignoring THEMA. This is a very common oversight for UK-based authors. BISAC alone will leave you invisible to significant parts of the UK and EU library and retail market.
- Conflating Amazon Browse Categories with BISAC. They are different systems serving different purposes. Both matter; neither replaces the other.
- Choosing vague or general subject codes. “FICTION / General” places your book alongside hundreds of thousands of other titles with no meaningful classification. Always choose the most specific code that accurately describes your book.
- Treating metadata as set-and-forget. Metadata can and should be revisited. If a book isn’t performing as expected, refreshed keywords or more precise subject categories can make a meaningful difference.
- Forgetting to register with Nielsen. UK authors who publish through Amazon KDP only – without also registering with Nielsen Title Editor – may find their books do not appear in Waterstones, Hive, or UK library catalogues.
Where to Submit and Manage Your Metadata
Nielsen Title Editor (UK and Ireland)
For UK-based authors, registering your book with Nielsen Title Editor is essential. Nielsen feeds its data to UK and Irish retailers including Waterstones, Amazon UK, Blackwell’s, and Hive, as well as to library systems. The basic service is free. Nielsen recommends submitting at least five months ahead of publication.
Register at nielsenisbnstore.com to purchase your ISBNs and access Title Editor. A paid Enhanced service is available, which unlocks the ability to add a long synopsis – some retailers, including Waterstones, only display the long description, so this is worth considering for your main title.
BDS – Bibliographic Data Services (UK library access)
BDS is the largest supplier of library-quality catalogue records in the UK and Ireland, and holds the British Library’s Cataloguing-in-Publication (CIP) programme contract. By submitting your book to BDS, you make it visible across every public library in the UK and Ireland, as well as academic and research libraries.
This is a step many independent authors miss entirely – yet it is free to submit via BDS’s online CIP form, which should ideally be completed at least sixteen weeks before publication. Submit at: cip.bdslive.com. For further information about working with BDS, visit bdslive.com/publishers.
Amazon KDP
KDP uses BISAC codes and its own browse category system. Authors enter seven keyword fields and select up to two browse categories. Metadata can be updated at any time via your KDP dashboard.
IngramSpark
IngramSpark requires a minimum of two BISAC codes and allows up to three, plus separate fields for THEMA subject codes and regional subjects. This makes IngramSpark particularly valuable for authors publishing across multiple markets: both classification systems can be entered in a single title setup. IngramSpark distributes to over 39,000 global retailers, schools, and libraries.
US Library Access: LCCN
For US-based authors, the closest equivalent to the UK’s BDS/Nielsen infrastructure is the Library of Congress Control Number (LCCN) – a free pre-publication identifier that helps US libraries catalogue and discover your book. Applying is straightforward via the Library of Congress’s PrePub Book Link system, and must be done before the book is published.
Apply at: loc.gov/programs/preassigned-control-number. Note that this programme is open to US-based publishers and authors only. For non-US authors, distribution through IngramSpark provides the best route into US library ordering systems via the Ingram wholesale network and WorldCat – the world’s largest library catalogue database.
Conclusion
Metadata will not write your book or design your cover. But it will determine whether anyone ever finds it.
The good news is that the classification systems and registration tools covered in this guide are free, well-documented, and accessible. BISAC codes are browsable at bisg.org. THEMA codes are searchable at ns.editeur.org/thema/en. Nielsen Title Editor is free to use. BDS registration is free. An LCCN costs nothing to apply for. The tools are there; they simply require the time and care to use them well.
Your book deserves to be found. Metadata is how that happens.
Need help with your book’s metadata?
At The Publishing Studio, we help independent authors get their metadata right from the start – from subject classification and keyword strategy to Nielsen registration and distribution setup. If you’d like support ensuring your book reaches every reader it deserves, we’d love to hear from you.
