Why KDP Rejects Your Cover (and How to Pass the First Time)

A KDP rejection email is almost always one of a short list of fixable problems. Here are the real causes, in order of how often they bite — and how to never see them again.

1. The full-cover file is the wrong size

A paperback cover is a single flat image: back + spine + front. Its size depends on your trim, page count, and paper. The formula:

• Spine width = pages × 0.002252 (white paper)
• Full width = (trim width × 2) + spine + 0.25" (bleed both sides)
• Full height = trim height + 0.25"

Design on a canvas that exact size at 300 DPI and the #1 rejection disappears. Confirm once in KDP's own cover calculator before you upload.

2. Fonts aren't embedded

This is the silent killer. KDP's printers won't have your font, so if it isn't embedded in the PDF, the file is rejected. Export from Canva via Download → PDF Print (it embeds automatically), or use a PDF/X preset in Affinity/Adobe. Verify in Acrobat: File → Properties → Fonts → every one must say "(Embedded)."

3. Something is in the bleed / too close to the trim

Keep all text and important art at least 0.25" inside the trim, and make sure your background extends fully into the 0.125" bleed (no white slivers). Printing shifts slightly; that margin is your safety net.

4. Spine text on a too-thin book

Books under 79 pages can't have spine text. If you want a titled spine, plan for at least 79 pages.

We package the full spec system, calculators, checklists, and font-embedding steps into Reject-Proof KDP — but the four fixes above will clear the vast majority of rejections on their own.