The 10-Point KDP Cover Pre-Upload Checklist

Every item on this list is a real rejection (or worse — an approved-but-ugly printed book) waiting to happen. Run through it after your design is finished and before you upload. Two minutes here saves a 24–72h review round-trip.

Dimensions

Cover file matches the final page count. Page count changed during formatting? The spine changed too. Re-run the calculator with the page count of the interior PDF you're actually uploading.
Paper type matches the cover math. Cream is thicker than white (0.0025" vs 0.002252" per page) — switching paper after design is the #1 cause of wrapped spines. Check the spine chart.
File is the full-cover size, not the trim size. You upload one wraparound file: back + spine + front + bleed. A 6 × 9 book's file is ~12.7" wide, not 6".
No spine text under 79 pages (paperback), and spine text has 0.0625" clearance from both spine edges.

Artwork

Background art fills the bleed. If your artwork stops at the trim line, a slightly shifted cut leaves white slivers on the edges. Extend it through all 0.125" of bleed (0.591" wrap for hardcover).
All text and logos are inside the safe area — at least 0.125" inside the trim line on every side. This includes subtitle, author name, and back-cover blurb.
Barcode zone is clear. Bottom-right of the back cover, 2" × 1.2": either leave it empty (KDP prints its own barcode) or place your own ISBN barcode exactly there. Artwork underneath gets covered either way.
300 DPI at final size. Screenshots and web images at 72 DPI print blurry. Check your export settings, not just the canvas.

File

Flattened PDF, fonts embedded or outlined. PDF is KDP's preferred format for print covers. No layers, no transparency, no crop marks in the export (guides are for your working file only — delete the template layer).
Preview in KDP's Print Previewer before publishing — it renders your actual file on the actual spine math. If the previewer shows spine text creeping onto a panel, go back to item 1.

Start from correct dimensions and half this list handles itself: generate your template →

Bonus: the three "approved but ugly" traps

Spine text on a thin book. Even at 90–120 pages it's technically allowed but hard to read and unforgiving of binding shift. Consider leaving it blank under ~100 pages.
Critical art at the spine fold. The fold can shift by 0.0625". Faces or straight lines that cross the spine will look broken half the time.
Dark, full-bleed back covers with white text at the edge. The most visible place for a slightly-off cut. Keep contrast elements well inside the safe zone.