Common reasons KDP or IngramSpark reject an uploaded file

How you'd notice this

You upload your interior or cover PDF and the platform returns an error instead of accepting the file for review, often naming a specific problem (margin violation, resolution too low, fonts not embedded, cover dimensions don't match spine width) rather than a generic failure.

Why it happens

Both platforms run automated checks against your exact trim size, page count, and file specs before a human ever sees the file. The most common rejection causes, in practice, are: text or images bleeding into the required safety margin (too close to the trim edge or the gutter), a cover file sized for the wrong page count (spine width is calculated from page count, adding or removing even a few pages changes the correct spine width), embedded fonts missing, image resolution below the platform's minimum, and a mismatch between the interior's declared trim size and the cover file's calculated dimensions.

How to fix it

• If page count changed at all after you built your cover file, rebuild the cover, spine width is directly tied to page count, and an old cover file will be rejected or misprint even if it looks fine.
• Re-check that no text or important image content sits inside your margin/gutter safety area, a violation here is one of the most common rejection reasons on both platforms.
• Re-confirm font embedding and image resolution using the checks described in this hub's Embedded-Font and Low-Resolution entries above, both are common, both are avoidable before you ever upload.
• Read the platform's specific rejection message closely, both KDP and IngramSpark name which check failed (margin, resolution, bleed, font, size mismatch), so you rarely have to guess which of the above applies.