Last reviewed by Robert Prime — July 2026
Verdict: If KDP rejected your book, start here. Find the exact error message in the table below, read the plain-English explanation, and follow the link to the step-by-step fix. Most rejections are a single formatting mistake — margin, cover trim, or font embedding — that takes five minutes to correct once you know which one it is.
KDP rejection emails are notoriously vague. You get something like "We found issues with your file" and a one-line error string that could mean ten different things. This page is the decoder ring: find the exact error Amazon showed you, read what it actually means, and follow the link to the detailed fix.
This is a different page from our interactive troubleshooter, which walks you through the fix step by step. This page is the reference hub — a flat lookup table you can search with Ctrl+F.
At publishing.co.uk we process formatting orders daily, so the error patterns below are drawn from what we actually see fail at upload — not theory.
At a glance
| What you see | What it means | The fix | Detailed guide |
|---|---|---|---|
Margins do not meet minimum requirements | Your gutter or outside margins are too narrow for your page count | Increase gutter margin — it scales with page count | Margin too small |
Cover file dimensions do not match | Your cover PDF is the wrong size for your trim + page count + paper type | Recalculate cover dimensions using KDP's cover calculator | Cover trim mismatch |
One or more fonts are not embedded | Your PDF references a font that isn't packaged inside the file | Re-export with "Embed all fonts" enabled | Font not embedded |
ISBN does not match | The ISBN in your metadata differs from the one on your copyright page or cover | Make all three locations identical — or remove your ISBN and use KDP's free one | ISBN mismatch |
Cover image resolution is below minimum | Your cover image is under 300 DPI at print size | Replace with a 300 DPI image at the correct pixel dimensions | Low-res cover |
Barcode placement issue | Your barcode overlaps the spine, bleeds off the edge, or is in the wrong position | Place the EAN-13 barcode in the lower-right quadrant of the back cover, fully inside the safe zone | Barcode placement |
Title does not match | The title on your cover or title page differs from what you entered in KDP metadata | Make the title identical in all three places — cover, title page, metadata | Metadata title mismatch |
Content quality issue | KDP's automated reviewer flagged low image resolution, placeholder text, or formatting problems in the interior | Check all images are 300 DPI, remove any placeholder text, review the KDP previewer page by page | Content quality flag |
EPUB validation failed | Your EPUB file does not pass EPUBCheck — malformed XML, missing metadata, or invalid structure | Run EPUBCheck locally, fix the errors it reports, re-upload | EPUB validation fail |
Spine width is too narrow for text | You have text on the spine but your book is too thin to support it | Remove spine text if your book is under 79 pages, or use our spine width calculator | Spine too narrow |
Bleed settings do not match file | You enabled bleed in KDP but your PDF doesn't extend content to the bleed edge (or vice versa) | Match your KDP bleed setting to your PDF — if bleed is on, content must extend 0.125" beyond trim | Bleed misconfigured |
File has an odd number of pages | Your PDF has an odd page count — KDP requires even | Add a blank page at the end of your manuscript | Odd page count |
How to use this table
- Open your KDP rejection email.
- Copy the error string Amazon gave you.
- Use Ctrl+F (or Cmd+F on Mac) to search this page for key words from that string.
- Read the "What it means" column for the plain-English explanation.
- Follow the "Detailed guide" link for the full step-by-step fix.
If your error isn't listed above, it may be a content-policy or rights issue rather than a formatting error. KDP's content guidelines cover those separately.
Error-by-error breakdown
Margins do not meet minimum requirements
The error: Margins do not meet minimum requirements for your selected trim size and page count.
What's happening: KDP calculates minimum margins based on your page count. The gutter (inside) margin must increase as page count grows because thicker books need more space for the binding. A 100-page book needs a smaller gutter than a 400-page book, and authors often use the same template for both.
The fix: Check your gutter margin against KDP's requirements for your exact page count. Outside, top and bottom margins must be at least 0.25" (6.35mm). For most books, we recommend 0.5" outside margins for a professional look.
Full guide: KDP error: margin too small
Cover file dimensions do not match
The error: Cover file dimensions do not match the expected dimensions for your book.
What's happening: Your cover PDF doesn't match the exact dimensions KDP expects for your combination of trim size, page count, and paper type. Spine width changes with page count — even a two-page difference can shift it. Switching between cream and white paper also changes spine width because the paper stocks have different thicknesses.
The fix: Use KDP's cover calculator to generate a template with your exact specs. Rebuild your cover to those dimensions. Re-export at 300 DPI.
Full guide: KDP error: cover trim mismatch
One or more fonts are not embedded
The error: One or more fonts in your manuscript are not embedded.
What's happening: Your PDF references a font that isn't packaged inside the file. KDP's print network needs the exact font data to render your text — it can't pull fonts from the internet. Bold, italic and bold-italic variants count as separate fonts, so a missing italic variant will trigger this even if the regular weight is embedded.
The fix: Re-export your PDF with font embedding enabled. In Word: File > Save As > PDF > Options > tick "ISO 19005-1 compliant (PDF/A)". In Acrobat: File > Properties > Fonts tab to verify every font shows "Embedded" or "Embedded Subset".
Full guide: KDP error: font not embedded
ISBN does not match
The error: The ISBN in your book file does not match the ISBN in your book details.
What's happening: KDP cross-checks the ISBN you entered in your metadata against what appears on your copyright page and (if visible) your back cover. If any of the three locations disagree, the file is rejected. This also triggers if you entered a KDP-assigned free ISBN but your file contains a different purchased ISBN.
The fix: Pick one ISBN and make it identical everywhere — KDP metadata, copyright page, and back cover barcode. If using KDP's free ISBN, remove any other ISBN from your files entirely.
Full guide: KDP error: ISBN mismatch
Cover image resolution is below minimum
The error: Cover image resolution is below the minimum required.
What's happening: KDP requires cover images to be at least 300 DPI at the final print size. A cover that looks sharp on screen may be far below 300 DPI when scaled to a 6x9" print cover. Upscaling a low-res image in Photoshop doesn't add real detail — KDP's checker can still flag it.
The fix: Start with a source image that is at least 300 DPI at your cover's physical dimensions. Height is always (trim height + 0.25" for bleed) × 300 — for a 9" tall book that is 2,775 px. Width is (2 × trim width + spine width + 0.25") × 300, where spine width = page count × 0.002252" (white paper) or × 0.0025" (cream). For a 250-page 6×9" paperback that works out at roughly 3,844 × 2,775 px for the full wrap-around cover. Use KDP's cover template generator rather than deriving this by hand — the numbers change with page count and paper stock.
Full guide: KDP error: low-res cover
Barcode placement issue
The error: Barcode placement does not meet requirements.
What's happening: Your EAN-13 barcode is overlapping the spine, running into the bleed zone, sitting on top of critical cover content, or placed on the front cover. KDP expects the barcode in the lower-right area of the back cover, fully inside the safe zone.
The fix: Position the barcode in the lower-right quadrant of the back cover, at least 0.25" from the trim edge on all sides and clear of the spine. If you're using a KDP-assigned ISBN, KDP can auto-place the barcode — just leave a white rectangle in the right spot.
Full guide: KDP error: barcode placement
Title does not match
The error: The title on your cover/interior does not match your book details.
What's happening: KDP compares the title in your metadata with what appears on your cover and title page. Even minor differences — a missing subtitle, different capitalisation, extra punctuation — will trigger a mismatch. Series titles appended to the cover but not the metadata are a common cause.
The fix: Make the title, subtitle and author name identical in all three places: KDP metadata, cover, and interior title page. Copy-paste from one to the others to avoid typos.
Full guide: KDP error: metadata title mismatch
Content quality issue
The error: We found quality issues with your book's content.
What's happening: This is KDP's catch-all flag. It can mean low-resolution interior images, placeholder or "lorem ipsum" text, excessively blank pages, missing content, or formatting that makes the book look unfinished. It sometimes triggers on content-thin books or books with a very high image-to-text ratio.
The fix: Check every interior image is 300 DPI at print size. Search your manuscript for "lorem", "TBD", "placeholder", "INSERT" and remove any. Review the KDP previewer page by page — if anything looks unfinished, fix it.
Full guide: KDP error: content quality flag
EPUB validation failed
The error: Your EPUB file did not pass validation.
What's happening: KDP runs EPUBCheck against your EPUB file. Common failures: malformed XML (unclosed tags, invalid entities), missing required metadata (dc:title, dc:identifier), invalid OPF manifest, or images referenced but not included in the package.
The fix: Download EPUBCheck and run it locally on your file. It will list every error with a line number. Fix them, re-export, re-validate, then re-upload. Most formatting tools (Atticus, Vellum) produce clean EPUBs — this error most commonly hits hand-coded or Word-exported files.
Full guide: KDP error: EPUB validation fail
Spine width is too narrow for text
The error: Spine width is too narrow for spine text.
What's happening: Amazon requires a minimum spine width of approximately 0.2" before text can appear on the spine. Below roughly 79 pages (depending on paper type), the spine is physically too thin for readable text. Putting text there risks it wrapping onto the front or back cover after trimming.
The fix: If your book is under 79 pages, remove all spine text and leave the spine blank or use only a subtle colour/pattern. Use our spine width calculator to check your book's spine width before designing the cover.
Full guide: KDP error: spine too narrow
Bleed settings do not match file
The error: Your bleed settings do not match your uploaded file.
What's happening: You told KDP your book has bleed (content extending to the page edge), but your PDF is sized for no-bleed (or vice versa). Bleed PDFs must be larger than the trim size — 0.125" wider on the outside edge and 0.125" taller on top and bottom. Text-only books almost never need bleed.
The fix: If your book has images or backgrounds that touch the page edge, enable bleed and ensure your PDF extends 0.125" beyond trim on three sides. If your book is text-only, disable bleed in KDP and use the standard trim-size PDF dimensions.
Full guide: KDP error: bleed misconfigured
File has an odd number of pages
The error: Your file has an odd number of pages.
What's happening: Print books are printed on sheets that fold into signatures — each physical sheet produces two pages. An odd page count is physically impossible to print. KDP rejects the file rather than silently adding a blank page.
The fix: Add one blank page at the end of your manuscript. This is standard practice — most professionally published books end with a blank page. Re-export and re-upload.
Full guide: KDP error: odd page count
Common mistakes
Fixing one error and ignoring the rest. KDP sometimes reports only the first error it finds. After fixing it, you re-upload and get a different rejection. Before resubmitting, check your file against this entire table — errors tend to cluster.
Using the KDP previewer but not reading the rejection email. The previewer catches visual problems. The rejection email catches technical ones (fonts, metadata, file dimensions). You need both.
Assuming "it looked fine on screen" means it will pass. Screen rendering and print-file validation are different processes. A PDF that looks perfect in Adobe Reader can still fail on embedded fonts, DPI, or page dimensions.
Re-uploading the same file hoping for a different result. KDP's automated checks are deterministic. The same file will fail the same way every time. Read the error, fix the cause, then re-upload.
Not checking the cover separately. Interior and cover are validated independently. A clean interior can still fail if the cover dimensions, barcode, or spine are wrong.
Worked example: fixing a multi-error rejection
Say you upload a 250-page paperback and KDP emails you: "We found issues with your file." You log in and see two errors flagged: Margins do not meet minimum requirements and One or more fonts are not embedded.
Step 1 — Margins. A 250-page book on white paper needs a gutter (inside) margin of at least 0.75". You check your PDF and find the gutter is set to 0.5". You increase it to 0.875" for comfortable readability, re-export the PDF.
Step 2 — Fonts. You open the re-exported PDF in Acrobat > File > Properties > Fonts. "Minion Pro Italic" shows as not embedded. You re-export from Word using Save As > PDF > Options > tick "ISO 19005-1 compliant (PDF/A)". Re-check: all fonts now show "Embedded Subset".
Step 3 — Sweep the rest. Before re-uploading, you check the lookup table above. Page count is 250 (even) — fine. No bleed needed for a text-only novel — fine. ISBN matches in all three locations — fine.
Step 4 — Re-upload. Both errors are resolved. KDP review passes.
Total cost of the fix: £0 if you do it yourself, or included free in a publishing.co.uk formatting order if we formatted the file originally.
FAQ
What do I do if my KDP error isn't listed on this page?
Check whether it's a content-policy issue (copyright, trademark, misleading content) rather than a formatting error. KDP's content guidelines cover those. If it's genuinely a formatting error we haven't listed, contact us and we'll add it.
How long does KDP review take after I fix and resubmit?
Typically 24–72 hours for the automated check. If your book was previously flagged for manual review, it can take up to two weeks. There is no way to speed this up.
Can I get rejected for the same error twice?
Yes, if you didn't fully fix it. For example, embedding fonts in the interior but not the cover PDF, or fixing the ISBN on the copyright page but not in the KDP metadata. Check every location the error could apply to.
Should I use KDP's free ISBN to avoid ISBN mismatch errors?
It's the simplest option if you're only selling on Amazon. But a KDP-assigned ISBN locks the book to Amazon, shows the publisher as "Independently published", and can't be used on other platforms. If you want wider distribution or your own imprint, buy from Nielsen (£93 single, £174 for 10).
Is there a way to check my file before uploading to KDP?
Yes. Run your file through our free KDP Readiness Score — it checks margins, fonts, image resolution, page count, bleed settings and more. Catching errors before upload saves you the 24–72 hour review cycle.
Want to skip the rejection cycle entirely? Our formatting service produces KDP-ready files built to pass review first time — from £69, delivered in 24 hours. Or run a free KDP Readiness Score on your existing file before you upload.
