KDP's error messages are written by a machine for a machine, and it shows. They tell you that something is wrong without much warmth about what — "the file does not meet requirements," "image quality is low," "content extends beyond the printable area." Read on their own, they are easy to mistake for a verdict on the whole book. They are not. Each one points at a single, specific, mechanical fault, and almost all of them are quick to fix once you know what the wording is actually describing.
Below are the errors you are most likely to meet on a print upload, in roughly the order of how often they appear, each translated into plain English with the fix.
"Your file is too large"
KDP accepts large files, but not unlimited ones, and image-heavy interiors are the usual cause. The trap is a PDF that has embedded every photograph at full camera resolution — far more detail than print needs.
The fix is to export the interior so that images are down-sampled to around 300 DPI at their printed size rather than left at source resolution, and to flatten the file. A correctly exported print PDF of a text-led book is usually modest; if yours is enormous, the images are almost always why.
"Page size does not match the trim size"
Every page in the interior has to be the exact trim you chose — 6 × 9, 5 × 8, whatever you set — with no stray pages of a different size. This error usually means the document was still set to a default like A4 or US Letter, or that one section (often the copyright page or a landscape image) slipped to a different size.
The fix is to set the page size to your trim before you lay anything out, so every page is born at the right dimensions, rather than resizing afterwards. Trim is the first decision in the whole process for exactly this reason — see choosing a book trim size.
"Fonts are not embedded"
When a PDF uses a font, that font has to be carried inside the file. If it is not, the press has nothing to print with and substitutes another face — your careful type reflows, and headings change shape. KDP catches this before it gets that far and stops the upload.
The fix is to export a print-ready PDF with all fonts embedded. This is a single export setting, not a per-font chore, and it is one of the central reasons a proper print PDF is safer than a word-processor file — covered in what is a print-ready PDF?
"Image quality is low" / "low-resolution images"
A monitor shows perhaps a quarter of the detail a printed page needs, so an image can look crisp on screen and still be too coarse for print. KDP flags interiors whose images fall well below 300 DPI at the size they are placed.
The fix is to replace the image with a higher-resolution source rather than enlarging the one you have — stretching a small image only spreads the same pixels thinner. The same 300 DPI rule governs covers, where it is one of the most common rejection reasons; see why your KDP cover was rejected.
"Content extends beyond the printable area"
Printing is mechanical, and the blade that trims each book moves within a small tolerance. KDP reserves a margin around every page and asks that text and important artwork stay inside it. Content that reaches too near the edge — or, on a no-bleed book, any artwork touching the edge at all — triggers this.
The fix is to pull live content inward to meet KDP's minimum margins: at least 0.25" on the outer edges of a no-bleed interior, more on the inner edge as the book thickens. The full margin picture is in margins and the gutter, and the reasoning behind the reserved edge is in why KDP rejects a book interior.
"The number of pages doesn't match between your cover and interior"
This one is about the pair. Your cover's spine width — and therefore its full-wrap size — is calculated from the interior's final page count. If you built the cover against a draft and then changed the interior, the two files describe different books, and KDP will not pair them.
The fix is order of operations: finalise the interior down to the last page, then build the cover from that locked page count. If the count has shifted, the cover has to be recalculated, because spine width moves with it.
"We are unable to process your file"
The catch-all. Usually it means the PDF is damaged, was saved with password protection or security restrictions, or was exported in a way the converter cannot read. Print files must be unlocked — a security-protected PDF cannot be printed from.
The fix is to re-export a clean, unprotected, flattened PDF from the source rather than trying to repair the rejected file.
Where Folio Format fits
The thread running through almost every error above is the same: a file that was exported as though it were a document, not a book — wrong page size, live fonts, source-resolution images, no awareness of trim or bleed. That is the gap Folio Format is built to close, by treating the trim, margins, page count and export as properties of the one book file, so the PDF that leaves it is already the size and shape KDP is about to check. The studio runs its pre-flight on the desk rather than after a rejection email; it is designed to help you export KDP-ready files and catch these common issues before upload. If you do hit one of these, the calm move is the same every time: read the message as a pointer to one fault, not a judgement on the book, fix that one thing, and re-upload.
Last checked 26 May 2026. Always confirm current Amazon KDP and IngramSpark specifications before uploading final files. Folio Format is designed to help users export KDP-ready files and catch common publishing issues before upload; it makes no claim about platform acceptance.