BISAC codes were once central to KDP category selection. The system changed in 2023. Here’s what BISAC codes are, how they work now on Amazon, and where they still matter for authors publishing wide.
| 8-minute read | All levels |
BISAC codes appear in a lot of self-publishing advice — and a lot of that advice is now outdated. The Book Industry Standards and Communications subject classification system has been a standard part of book metadata for decades, and for years KDP authors selected BISAC codes directly as part of their category assignment process. That changed in 2023, when Amazon overhauled how KDP categories work. Understanding what changed, what BISAC codes still do, and where they remain relevant will help you navigate category decisions without confusion.
What BISAC Codes Are
BISAC codes are a standardised subject classification system maintained by the Book Industry Study Group (BISG), a US trade association. The system consists of a hierarchical list of subject headings — currently around 3,500 codes — each represented by a short alphanumeric string. For example, FIC022000 represents “Fiction — Mystery & Detective — General”, and BUS070000 represents “Business & Economics — Personal Finance — General.”
The purpose of BISAC codes is interoperability across the book industry supply chain. When a publisher submits a book’s metadata to a retailer, library, or distributor, BISAC codes provide a standardised signal about the book’s subject that every system in the chain can interpret consistently. Without standardised subject codes, every retailer would need to map your custom genre descriptions to their own internal categories — an impractical process at scale. BISAC codes solve this by giving the entire industry a shared vocabulary.
For readers browsing Amazon, BISAC codes are invisible. They’re a backend metadata element, not a consumer-facing label. Readers see Amazon’s own category names in the browse sidebar and on product pages, not BISAC strings. The relevance of BISAC codes to your daily publishing decisions depends entirely on where and how you publish.
How BISAC Codes Changed on KDP in 2023
Prior to mid-2023, KDP authors selected two BISAC codes directly during the book setup process. These BISAC selections were one of the primary inputs into Amazon’s category placement system. Authors could also request up to ten additional categories by contacting KDP support — a manual process that gave prolific self-publishers broad category coverage.
The 2023 update replaced direct BISAC selection with Amazon’s own category taxonomy. Authors now choose up to three categories per format from Amazon’s hierarchical browse category structure — the same structure readers see when browsing. Amazon’s system then automatically derives the corresponding BISAC codes from your category selections in the background. You don’t choose BISAC codes; Amazon infers them from the Amazon categories you select.
This change removed BISAC codes from the author-facing KDP workflow entirely for Amazon purposes. You can no longer override Amazon’s BISAC assignment, and you don’t need to know what BISAC code your book has been assigned. The KDP dashboard doesn’t show you the derived BISAC codes — they exist in the backend metadata but aren’t surfaced to the author.
What this means in practice: If you’re publishing only on Amazon KDP, you don’t need to think about BISAC codes at all. Focus entirely on choosing the right Amazon category paths. The BISAC codes will be handled automatically.
Where BISAC Codes Still Matter
BISAC codes remain directly relevant for authors publishing through channels outside Amazon. IngramSpark, Draft2Digital, Smashwords, and other wide-distribution platforms still use BISAC codes as a core metadata requirement. When you set up a title through IngramSpark for distribution to Barnes & Noble, libraries, independent bookshops, and international retailers, you select BISAC codes directly and those codes are submitted as part of your title metadata to every retailer in the distribution network.
Library metadata is particularly BISAC-dependent. Libraries use BISAC codes to classify and shelve books in their cataloguing systems — a correctly assigned BISAC code determines whether your book appears in a librarian’s search results when they’re purchasing for a particular subject collection. Authors aiming for library distribution should research and apply BISAC codes carefully through their wide-distribution channels, even if those codes are invisible on Amazon.
Some metadata aggregation services and book discovery platforms also use BISAC codes for classification. Goodreads genre assignments, for example, are partly informed by BISAC codes submitted through publisher metadata feeds. Authors publishing wide who want consistent genre classification across discovery platforms benefit from choosing BISAC codes deliberately in their wide-distribution metadata, rather than leaving the assignment to whatever default their distributor infers.
Choosing BISAC Codes for Wide Distribution
If you are publishing through IngramSpark or another wide distributor and need to select BISAC codes directly, the BISG maintains a publicly accessible subject heading list at bisg.org. The list is hierarchical — you’ll find a top-level section (FIC for fiction, BUS for business, HEA for health, and so on) with progressively specific sub-codes beneath it. Always select the most specific code that accurately describes your book’s primary subject, plus up to two additional codes if your book legitimately spans multiple subjects.
For fiction, the relevant BISAC top-level section is FIC, with sub-codes for every major genre and subgenre. For nonfiction, identify your subject domain first — SEL (Self-Help), HEA (Health & Fitness), FAM (Family & Relationships), etc. — then find the most specific sub-code within it. The full BISAC list runs to thousands of entries and is updated annually, so it’s worth checking the current version rather than relying on older lists that may reference deprecated codes.
When publishing both on Amazon KDP and through a wide distributor like IngramSpark, your BISAC codes for the wide version should reflect the same genre and subject as your Amazon category selections, even though they’re maintained in separate systems. Consistency in your metadata across platforms ensures that aggregators, comparison sites, and library systems classify your book consistently — an important factor if you’re building discoverability across multiple retail channels rather than relying solely on Amazon.
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The Historical Context: Why BISAC Still Comes Up
If you’ve been publishing since before 2023, you may remember selecting BISAC codes as part of the standard KDP upload workflow. The interface presented a searchable dropdown of BISAC subject headings, and your two selections anchored your primary category placements. Industry training materials, YouTube tutorials, and self-publishing blog posts from that era are full of BISAC selection advice — which specific codes perform best, how to pick the most strategic BISAC for discoverability, and how to combine codes across different subject branches to maximise category coverage.
Much of that content is still indexed and ranking in search engines, which is why so many authors arrive at the category selection stage in 2026 with BISAC on their minds. The underlying category strategy thinking in those older guides is often still valid — the logic of choosing an accurate primary category alongside a less-competitive secondary placement hasn’t changed. But the specific mechanism (selecting BISAC codes in KDP) has been replaced, and any advice tied to the old dropdown interface or the support-request process for additional categories no longer applies.
BISAC Codes in Amazon’s Metadata Backend
Even though authors no longer interact with BISAC codes directly in KDP, the codes themselves haven’t disappeared from Amazon’s systems. When you select an Amazon store category — say, “Books → Mystery, Thriller & Suspense → Mystery → Cozy Mysteries” — Amazon maps that selection to the closest corresponding BISAC code in its backend systems. That BISAC code is then included in the book’s industry metadata, which is used in data feeds to third-party catalogues, comparison shopping services, library systems, and book discovery platforms that still rely on BISAC as a common language.
This automatic mapping is generally accurate for well-established genre categories where clear BISAC equivalents exist. It’s somewhat less precise for highly specific Amazon subcategories that don’t have a clean BISAC equivalent — Amazon’s taxonomy has become more granular than BISAC in some genre fiction areas, and the auto-derived BISAC code may be a broader category than the Amazon selection. For most authors publishing on Amazon alone, this imprecision doesn’t matter. For authors who also care about metadata quality in library and wide-distribution contexts, manual BISAC selection through IngramSpark provides more control.
Practical Guidance: Amazon-Only vs Wide Publishing
If you publish exclusively through Amazon KDP, your BISAC workflow is zero-effort: select the best Amazon categories for your book, and let Amazon handle BISAC derivation automatically. Spend your metadata research time on Amazon’s category taxonomy, not on BISAC codes you’ll never interact with directly.
If you publish through both Amazon KDP and IngramSpark (for wide distribution to other retailers, libraries, and international markets), you maintain two separate sets of category metadata: Amazon categories in KDP and BISAC codes in IngramSpark. These should be aligned — your BISAC selections in IngramSpark should describe the same genre and audience as your Amazon category selections — but they’re managed separately in each platform’s interface. IngramSpark’s setup process walks you through BISAC selection with its own dropdown interface, and their help documentation provides guidance on choosing appropriate codes.
The key practical point for wide publishers is not to confuse the two systems. Amazon category optimisation strategies (targeting specific Amazon category paths for competition analysis and badge potential) don’t translate directly to BISAC selection. BISAC is a much flatter taxonomy with fewer granular subdivisions — you can’t target “cozy mysteries featuring cats” as a BISAC code the way you can as an Amazon category. Focus Amazon-specific strategy on Amazon’s taxonomy and approach BISAC as a broader classification exercise for non-Amazon distribution.
Regardless of which distribution channels you use, a clean, accurate book description is the foundation of correct category assignment across all systems. Professional manuscript proofreading ensures your book and its listing copy are ready for distribution through every channel you choose.
A Quick Reference: BISAC in 2026
New KDP author publishing exclusively on Amazon: you will never encounter BISAC codes in your workflow. Select Amazon categories in the KDP dashboard and ignore BISAC entirely. Existing KDP author who used to select BISAC codes: your previously selected codes have been replaced by Amazon’s automatic derivation from your current category selections. Nothing needs updating on your end — it happened automatically with the 2023 system change.
Publishing wide through IngramSpark alongside KDP: you’ll select BISAC codes separately in IngramSpark’s setup process. Treat this as a distinct metadata task from your Amazon category selection. Align the BISAC codes with your Amazon categories in terms of genre and subject, but use IngramSpark’s own interface to make the selection. Wondering whether your Amazon BISAC derivation is affecting discoverability: it isn’t something you can directly see or control. Amazon’s category placement is driven by your Amazon category selections and metadata signals. If your Amazon category placements are correct and relevant, the derived BISAC is correct by definition.
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