KDP Quality Check Failed: A Comprehensive Troubleshooting Guide

Last reviewed by Robert Prime — March 2026

We see this come through our formatting queue at publishing.co.uk regularly, so the patterns and fixes here are based on what actually works at upload.

Introduction: What Does "KDP Quality Check Failed" Mean?

If you’ve uploaded your book files to Amazon’s Kindle Direct Publishing (KDP) platform and encountered the dreaded “KDP Quality Check Failed” message, you’re far from alone. This error can feel like hitting a brick wall after all your hard work writing and preparing your manuscript. It’s frustrating, especially when the message is vague and doesn’t explain exactly what went wrong.

In essence, KDP quality checks are automated and manual validations Amazon runs on your upload to ensure your files meet their strict technical and formatting requirements for print and digital publication. When these checks fail, it means your files — be it your manuscript interior, cover, or metadata — have issues that will prevent your book from going live. The process can cost you time. But with the right knowledge, you can avoid common pitfalls and speed up your publishing journey.

This guide is built specifically for UK authors, giving you a detailed, no-nonsense walkthrough of the causes, fixes practices around KDP quality check failures. I’ll share insider tips from my 25 years of eCommerce experience and how I built publishing.co.uk to solve exactly these problems, so you don’t have to endure the same headaches.

Before you start troubleshooting your KDP quality check failure, it’s essential to understand a few basics:

• File Types Matter: KDP accepts PDF for print interiors and EPUB or DOCX for Kindle eBooks. Uploading the wrong type or a corrupted file triggers failures.
• Trim Size and Bleed: Your book's physical dimensions must align with KDP’s supported trim sizes (e.g., 5"x8", 6"x9"). You must set bleed correctly if your content runs to the edge.
• Fonts and Images: Fonts must be embedded in PDFs, and images should meet resolution standards (300 dpi minimum).
• ISBN and Barcodes: For print books, you need a valid ISBN (Nielsen is the UK’s official provider). Free KDP ISBNs list Amazon as the publisher, which may not suit serious UK authors wanting full control.
• Margins and Gutter: Proper margins ensure text doesn’t get clipped during printing. The gutter margin accounts for the book’s binding.
• Metadata Accuracy: Title, author name, and description must be consistent and comply with Amazon’s guidelines.
• UK VAT and Pricing: Print books are zero-rated for VAT in the UK, but pricing must consider Amazon’s royalty structures and printing costs.

Remember, Amazon’s KDP system is designed with US-centric defaults. UK authors need to double-check settings, especially ISBN and pricing, to avoid hiccups.

When you receive a KDP Quality Check Failed notification, it usually comes with (or without) an error code or message. Here’s a detailed process to identify and fix the issue:

1. Review the Error Message Carefully

Amazon sometimes provides a specific error code or description. This is your first clue:

• File format not supported
• Margins too small
• Bleed settings missing or incorrect
• Fonts not embedded
• Image resolution too low
• ISBN missing or invalid
• Cover file issues (wrong dimensions, low DPI)

If the error is vague, proceed with the following checks.

2. Verify Your Manuscript File Format

• For print books, ensure the interior file is a high-quality PDF with embedded fonts.
• For Kindle eBooks, upload a validated EPUB or DOCX (properly formatted).
• Avoid using Word DOC files directly for print — KDP rejects these.
• Run your EPUB through tools like EPUB Validator (https://validator.idpf.org) to catch structural errors.

UK Tip: Many UK authors make the mistake of uploading A4-sized documents (the standard UK paper size) instead of US Letter or KDP-supported trim sizes. Always convert your manuscript to a KDP trim size before export.

3. Check Trim Size and Page Count

• Confirm your manuscript matches the selected trim size exactly.
• KDP only supports certain trim sizes; selecting an unsupported size causes failure.
• Page count must be within KDP’s limits (usually between 24 and 828 pages for print).
• Adjust page count by adding blank pages if necessary to meet binding requirements (odd page counts).

Pro Tip: To check your trim size in Word, go to Layout > Size > More Paper Sizes, and set the exact dimensions in inches or millimetres (KDP accepts both). For example, 6"x9" trim size corresponds to 152.4mm x 228.6mm.

4. Inspect Margins and Bleed Settings

• Open your PDF in Adobe Acrobat or similar.
• Check margins: KDP recommends minimum 0.25” (6.35 mm) margins on all sides, with an extra gutter margin based on page count.
• Set bleed for full-page images or backgrounds that extend to the edge (usually 3mm beyond the trim).
• In Word, use Layout > Margins > Custom Margins to set precise margins before exporting to PDF.

How to set bleed in Word: Word doesn't support bleed natively. You’ll need to create your content slightly larger than trim size and then crop in Acrobat or use dedicated software like Adobe InDesign.

5. Confirm Fonts Are Embedded

• In Adobe Acrobat, go to File > Properties > Fonts to check embedding status.
• Non-embedded fonts cause rejections or display errors.
• Use widely supported fonts (avoid decorative fonts like Papyrus or Bleeding Cowboys).

UK Author Anecdote: I recall a British author who used a font called “Gill Sans Nova” without embedding it. KDP rejected the file, and the author lost two days trying to identify the problem. Always embed fonts to avoid this.

6. Validate Image Resolution and Colour Mode

• Images must be at least 300 dpi for print quality.
• Use CMYK colour mode for print files, although KDP converts RGB automatically (but this can cause colour shifts).
• Avoid low-resolution or stretched images which trigger quality check errors.

UK Market Note: UK printers commonly use CMYK, and UK readers expect print quality that reflects that standard. While KDP converts RGB, it’s safer to supply CMYK files to avoid surprises.

7. Verify ISBN and Barcode

• In the UK, purchase ISBNs from Nielsen (https://www.nielsenisbnstore.com) at £93 for a single ISBN or £174 for a block of 10 (prices as of 2024).
• Do not rely on free KDP ISBNs if you want to control your publishing imprint.
• Ensure the ISBN barcode on your cover is correctly formatted (EAN-13 format) and positioned according to KDP guidelines.

Critical: UK bookstores and libraries require valid Nielsen ISBNs. Free KDP ISBNs list Amazon as the publisher, which disqualifies you from many distribution options.

8. Check Cover File Specifications

• Cover files for print must be PDF with exact dimensions (including back cover, spine width, front cover).
• Spine width depends on page count and paper type; use a calculator (like the one KDP provides).
• Cover images must be 300 dpi minimum.
• For Kindle eBooks, covers must be JPEG or TIFF with recommended dimensions (ideal ratio 1.6:1).

Step-by-step for cover calculation:

• Go to KDP’s Cover Calculator: https://kdp.amazon.com/en_US/cover-calculator
• Input your page count and paper type (cream or white) to get spine width
• Add spine width to front and back covers to get total cover size
• Design your cover in your preferred software with these exact dimensions.

9. Upload Files Separately and Preview

• Upload interior and cover files individually to isolate which file causes the failure.
• Use KDP’s Previewer Tool to check for errors before submitting.
• Previewing on different devices (Kindle app, print preview) helps catch hidden issues.

Menu Path:

• Log in to KDP
• Click Create a New Title or select your existing title
• Upload your manuscript and cover under the Paperback Content or Kindle eBook Content section
• Click Launch Previewer to see how your book appears and spot errors

10. Seek Professional Help If Needed

• If the above steps are overwhelming, consider a professional format service.
• Publishing.co.uk offers UK-focused automated formatting that aligns with KDP’s requirements and saves hours of frustration.

Common Terminology and Definitions

Before diving deeper, understanding these terms will help you navigate KDP’s requirements:

Most KDP help online is US-centric, so here are practical points UK authors should prioritise:

ISBN Purchase and Usage

• Unlike the US (Bowker), UK authors must buy ISBNs from Nielsen.
• Prices as of 2024: £93 for a single ISBN, £174 for a block of 10.
• Using free KDP ISBNs lists Amazon as the publisher, which can harm your author brand and rights.
• If you plan to sell through UK bookstores or libraries, owning your ISBN is crucial.

Example:
I worked with a London-based author who initially used a free KDP ISBN. When trying to stock her book in Waterstones, the retailer rejected it because the ISBN listed Amazon as the publisher, not the author’s own imprint. She then bought a Nielsen ISBN, updated metadata, and resubmitted the files — the book was accepted within 48 hours.

VAT and Pricing Implications

• Print books in the UK are zero-rated for VAT, reducing your tax burden on sales.
• However, eBooks have VAT applied at different rates depending on the platform and market.
• Pricing your book on KDP should consider print cost (which varies by page count and colour), Amazon royalty percentages, and competitive UK market pricing.
• Setting too low a price can trigger quality checks if minimum royalties aren’t met.

Pricing Example:
For a 200-page black-and-white paperback with cream paper, printing costs are approximately £2.45 per copy on KDP. Set your list price at £6.99 — Amazon deducts printing costs plus a 60% royalty on the remainder, leaving you roughly £2.41 per sale. Pricing below £4.25 often triggers quality check warnings about minimum royalty thresholds.

Paper Type and Print Options

• KDP offers white or cream paper for print books. Cream is preferred for fiction in the UK market for easier reading.
• Paper choice affects print cost and spine thickness, which impacts cover design.
• KDP’s print quality is decent but not premium; consider UK-based printers if you want higher-end finishes.

UK Author Insight:
I’ve seen many UK authors prefer cream paper for novels as it’s easier on the eye, aligning with UK trade publishing standards. This choice is critical when setting up your KDP files to avoid bleed and spine miscalculations.

• Many UK authors compete globally via Amazon but must optimise KDP files to avoid quality check failures that delay listings.
• Investing in professional formatting aligned to UK standards can pay off in smoother publishing and better market reception.

From my experience formatting thousands of books and dealing with frustrated authors, these are the top causes of KDP quality check failures:

1. Using Cheap or Inexperienced Formatters

I once hired a formatter charging £130 who delivered a PDF with inconsistent margins and non-embedded fonts. I wasted days fixing it. Indirect costs like wasted hours can exceed £300 depending on your time value.

Frequently asked questions

How long do KDP rejections usually take to come through?

Usually within 24-72 hours of upload. Rejections show in your KDP Bookshelf as "Needs attention". Email notification can lag — check the dashboard.

Can I just re-upload the fixed file or do I have to start a new title?

Re-upload the corrected file on the same title. KDP versions your interior and cover separately. The new file replaces the old; sales history and ASIN are preserved.

Will my book go down for sale while I fix and re-upload?

Only briefly — usually a few hours while KDP re-reviews. Existing copies in transit still ship. Plan re-uploads outside of major promotion windows.

Can I appeal a rejection if I think KDP got it wrong?

Yes — KDP Support → Help → Contact Us → Paperback or Kindle → "I disagree with this rejection". Include screenshots and a clear statement of why the file meets spec. Response usually within 48 hours.

Does using publishing.co.uk's formatting service avoid this rejection?

Yes — our process pre-flights against all 30+ known KDP rejection rules before delivery. We've shipped 500+ files through KDP. If KDP does reject for a covered reason, we re-do it free.

About this guide

Written by Robert Prime for publishing.co.uk. Last reviewed May 2026. Specs and pricing change — verify current figures with the linked sources before relying on them.

Related guides

• Kdp Error Content Quality Flag
• Word To Kdp Guide
• What Is Kdp
• Thriller Novel Kdp Formatting
• Self Help Kdp Formatting

External references

• For current UK indie publishing trends, see the ALCS Author's Earnings report.