KDP Error: Insufficient Gutter

This error indicates that your book’s Inside Margin is too small, and that KDP has detected content that crosses the threshold for KDP’s minimum margins.

This can happen if you’ve decreased the Inside Margin to be lower than Vellum’s default (0.875 inches), or if your book is longer than 700 pages. Because KDP’s checks are extremely sensitive, it can even happen with a value that matches KDP’s minimum.

To address this error, you’ll need to open Print Settings and increase your book’s Inside Margin:

When adjusting, we recommend choosing a value that is larger than KDP’s minimum. This allows some extra room for KDP’s checks, which will raise errors if even a single pixel crosses their minimum value.