Last reviewed by Robert Prime — May 2026
Quick Answer: Your PDF includes printer crop/registration marks visible inside the bleed area. KDP's automated printers don't use these and they appear on the final book. Re-export without crop marks: in Word, File → Print → uncheck crop marks. In InDesign, File → Export → tick 'No Marks'.
Full reasoning, why-it-happens, and the exact fix below.
UK note: UK-specific considerations apply — ISBN purchases go through Nielsen (not Bowker), VAT rules differ from the US (print books are zero-rated; ebooks carry 20% VAT), and GDPR applies to any email/customer data. See our UK self-publishing guides for specifics.
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.
What this error means
Crop marks are short corner lines printed outside the trim area to show a press operator where to cut. KDP's printers are fully automated and use the PDF's internal trim box to slice pages — they don't need (or want) crop marks. KDP's spec explicitly states "no crop marks, annotations, bookmarks, or comments in PDF."
If the checker detects printer marks, the rejection reads "Your PDF contains printer marks that must be removed." The same rule covers registration marks (used to align colour plates), colour bars (calibration stripes), page information labels, and slug area marks.
This affects covers far more than interiors — designers experienced with commercial print add crop marks by reflex, since they're required by every UK litho printer outside KDP.
📎 Source: KDP's authoritative documentation on this rule is at KDP's print PDF requirements.
Why it happens
Designer reflex. A cover designer who works mostly with Lulu, Ingram Spark, or local UK printers adds crop marks automatically. They forget that KDP is different.
InDesign's "PDF/X-1a" preset adds marks by default. Under Marks and Bleeds, "All Printer's Marks" is often left ticked from a previous job.
Illustrator export. When saving as PDF for print, Illustrator's "Marks and Bleed" tab defaults to having crop marks on.
Canva Pro has a "Crop marks and bleed" checkbox — toggling it on adds both. If you need bleed but not crop marks, Canva can't do both selectively. You have to add bleed in design dimensions and untick the checkbox.
Acrobat / Preview "Print to PDF" sometimes adds page labels and printer marks depending on print preset settings.
Templates from print-on-demand competitors (Ingram, Lulu) ship with crop marks baked in. Re-using those templates without modification fails KDP.
The fix
Step 1: Identify whether your file has printer marks. Open in Acrobat → Print Production → Add Printer Marks → if the dialogue's "Crop Marks" is already ticked, your file has them. Cancel without changes.
Step 2 (InDesign): File → Export → PDF → Marks and Bleeds tab → uncheck all printer marks (Crop, Bleed, Registration, Colour Bars, Page Information). Leave "Use Document Bleed Settings" ticked so bleed is preserved without marks. Export.
Step 3 (Illustrator): File → Save As → Adobe PDF → Marks and Bleeds → uncheck "All Printer's Marks". Save.
Step 4 (Affinity Designer / Publisher): File → Export → PDF → Marks → uncheck Crop Marks, Bleed Marks, Registration Marks. Keep "Include bleed" ticked. Export.
Step 5 (Canva Pro): Download → PDF Print → uncheck "Crop marks and bleed". This removes both. If you need bleed, you must have built it into the document size from the start (e.g. 6.125 × 9.25 for a 6×9 with bleed) rather than relying on Canva to add it at export.
Step 6 (Acrobat post-fix): If you can't easily re-export, open the PDF → Print Production → Add Printer Marks → cancel → then Tools → Edit PDF → delete the corner mark objects by hand. This is fiddly but works. Alternatively, Print Production → Set Page Boxes → uncheck "Show all boxes" and crop to the trim box only. Save As.
Step 7: Verify. Open the new PDF in Acrobat → View at 100% → zoom to each corner. There should be no small black lines just outside the page corners. Then Print Production → Output Preview → no "Trim Marks" listed.
Step 8: If you needed bleed, confirm it's still present — the PDF page size should equal trim + bleed (e.g. 6.125 × 9.25" for a 6×9 with bleed), not trim only.
How to pre-flight it
Our free KDP Readiness Score detects crop marks, registration marks, and other printer marks by parsing the PDF's content stream. Plus 30+ other KDP rules. Run it before submission and you'll catch the marks while still in your design tool.
Related errors
- KDP error: bleed misconfigured
- KDP error: cover dimensions don't match interior
- KDP error: transparency not flattened
FAQ
Why does Lulu accept crop marks but KDP doesn't? Different print workflows. Lulu's press uses traditional sheet-fed offset where crop marks help. KDP uses POD (print-on-demand) digital presses that trim automatically from PDF metadata.
Does the "trim box" do the same job as crop marks? Yes — modern PDFs include a TrimBox that tells the printer exactly where to cut. KDP uses this. Crop marks are visual redundancy that the press doesn't need.
Can I leave registration marks but remove crop marks? No — KDP rejects all printer marks. Remove every type.
My cover from a freelance designer has crop marks — do I send it back? You can either send it back asking for a clean export, or remove the marks yourself in Acrobat (steps above). The fix takes about five minutes if you know where the controls are.
Frequently asked questions
Why did my export include crop marks by default?
InDesign, Affinity Publisher, and Scribus all default to including marks for professional offset printing. Disable them in the export dialog — they're not needed for KDP's print-on-demand.
How do I tell whether my PDF has crop marks I didn't add?
Open in any PDF viewer. Crop marks appear as small lines in the corners outside the trim area. They often come from print-shop PDF presets being used by accident. The free KDP Readiness Score flags them automatically.
Will publishing.co.uk remove crop marks from a file I've already exported?
Yes — re-exporting through Acrobat Pro with the correct PDF/X-1a:2001 preset (and no printer marks selected) strips them cleanly. We then verify the trim box matches the intended trim size.
Why does KDP reject crop marks if they're outside the page area?
KDP's print machinery uses the page boundary to position the cut. Crop marks that fall outside the trim are usually fine, but marks that overlap the trim line cause cuts in wrong places. Removing them entirely is simpler than debugging the boundary.
Related KDP error fixes
If you got the rejection above, you may also want to check these related issues — they tend to cluster:
Full list: KDP formatting errors hub · KDP rejection fixes hub · KDP rejected my book
About this guide
This page is part of a series of UK-focused KDP rejection guides at publishing.co.uk, each documenting a specific reason KDP can reject a print or Kindle file and the exact fix. Written by Robert Prime — founder of publishing.co.uk, co-runs the LoveReading network, and has overseen 500+ KDP submissions through formatting work in this category (print pdf).
If you'd rather have someone else handle this and the other 35 issues KDP checks for, our formatting service is from £69 with a 3-day turnaround and a 100% KDP-acceptance guarantee.
Run a free KDP Readiness Score on your file before you upload — catches this issue and 35 others, in 60 seconds.
External references
- Amazon KDP Help — official KDP documentation
- Author Earnings reports (ALCS) — UK author income surveys
