Last reviewed by Robert Prime — July 2026
What this is: A complete formatting checklist for uploading paperbacks and ebooks to Amazon KDP. Every item below is drawn from KDP's own specifications. Work through it before you hit "upload" — most rejections and quality flags come from skipping one of these steps.
Paperback interior checklist
Trim size
- Chosen a trim size that KDP supports (common UK choice: 129 × 198 mm / 5.06 × 7.81 in, B-format)
- Confirmed your chosen trim is available for your marketplace — not all trims are available in all regions
- Interior page size in your PDF matches the chosen trim exactly — no scaling, no "fit to page"
Margins and gutter
- Using mirrored margins (inside/outside, not left/right) so the gutter swaps sides on each page
- Inside margin (gutter) meets KDP's minimum for your page count — the gutter requirement increases with page count; check the current table on KDP's help pages
- Outside margin is at least 6.4 mm (0.25 in)
- Top margin is at least 6.4 mm (0.25 in)
- Bottom margin is at least 6.4 mm (0.25 in)
- No text, images, or page numbers fall inside the margin area
Fonts
- All fonts are embedded in the PDF — no system-font dependencies
- Body text is a readable size (11–12 pt for most genres; never below 7 pt, which is KDP's minimum)
- Font licensing permits commercial embedding (check your licence terms)
- No colour fonts in a black-and-white interior (colour text in a B&W file prints as grey)
Page numbers
- Page numbers (if used) are outside the margin area
- Front matter pages (title, copyright, dedication) either omit page numbers or use roman numerals — this is convention, not a KDP rule
- No page numbers on blank pages
- Page numbers are consistent in position and style throughout
Front matter
- Title page — matches the title entered in KDP exactly
- Copyright page — includes copyright notice, year, author name, and "All rights reserved" or equivalent
- ISBN listed on copyright page (if using your own ISBN)
- Table of contents — optional for fiction, strongly recommended for non-fiction
- Dedication, foreword, acknowledgements — positioned before the body text
Back matter
- About the author section
- Also by page listing other titles (if applicable)
- Review request or reader magnet page — positioned after the main text
- No blank pages at the very end unless needed to reach a page count minimum
ISBN
- Decided whether to use a free KDP ISBN (Amazon-only, cannot be used elsewhere) or your own ISBN (purchased from Nielsen in the UK)
- If using your own ISBN, it is entered in KDP and printed on the copyright page
- ISBN matches the format — a paperback ISBN is different from an ebook ISBN and different from a hardcover ISBN
- If using your own ISBN, the publisher name registered with Nielsen matches what you want displayed
File format
- Interior uploaded as a PDF (KDP's recommended format for paperback)
- PDF is print-ready — not a screen-optimised or web-quality PDF
- No password protection, security settings, or encryption on the PDF
- No layers, transparency, or form fields in the PDF
- No spot colours — all colour must be CMYK or greyscale, not RGB (for colour interiors)
Page count
- Total page count is within KDP's allowed range for your trim and ink type (minimum 24 pages for most trims; maximum varies — currently 828 for black-and-white on some trims)
- Page count includes all front matter, back matter, and any blank pages
- Aware that page count directly affects printing cost and therefore royalty
Paperback cover checklist
Cover file
- Cover submitted as a single PDF containing front, spine, and back in one spread — or built using KDP's Cover Creator
- PDF dimensions match KDP's calculated cover size for your trim, page count, and paper type — use the KDP cover calculator or template generator
- Resolution is 300 DPI minimum
- Colour mode is CMYK (not RGB)
- No password protection on the PDF
Bleed
- 3.175 mm (0.125 in) bleed on all four outer edges (top, bottom, outside front, outside back)
- Background images and colours extend to the bleed edge — not just to the trim line
- No critical text or images within 3.175 mm of the trim line (the "safe zone")
Spine
- Spine width calculated correctly for your page count and paper type — use KDP's spine calculator
- Spine text (if any) is centred and does not extend into the front or back cover area
- Spine text is only added if the book is over 79 pages — KDP does not print spine text below that (spine width under about 0.2 in / 5 mm)
Barcode area
- Back cover has a clear area for the KDP-generated barcode — bottom-right corner, at least 50.8 × 31.75 mm (2 × 1.25 in)
- No text or images placed where the barcode will print
- If using your own ISBN with a barcode, it is positioned in the barcode area and matches the ISBN entered in KDP
Ebook (Kindle) checklist
File format
- Manuscript uploaded as EPUB or DOCX (KDP converts to Kindle format) — or as KPF from Kindle Create
- If using EPUB, it validates against EPUB 3 standards (use the W3C EPUBCheck validator)
- No PDF upload for ebook — KDP does not accept PDF for Kindle
Content and structure
- Working table of contents with hyperlinked entries — KDP flags ebooks without a navigable TOC
- Chapter breaks use proper heading tags or page breaks — not just extra line spacing
- Images are embedded, not linked — broken image links cause upload failures
- Image resolution is at least 300 DPI for photographs; 72 DPI minimum for simple graphics
- Cover image is set as the ebook cover (not just embedded as page one)
Ebook cover
- Cover image is at least 1600 × 2560 px (ideal ratio 1:1.6)
- File format is JPEG or TIFF
- File size under 50 MB
- No pricing, "free", or promotional text on the cover — KDP may reject it
Pricing (70% royalty band)
- To qualify for the 70% royalty rate, list price must fall within $2.99–$12.99 (or £1.77–£12.99 for amazon.co.uk) — updated July 2026
- File delivery cost is deducted from the 70% royalty — large files (many images) reduce your net royalty
- If your price falls outside the 70% band, the 35% royalty rate applies automatically
Pre-upload final checks
- Run a free KDP Readiness Score to catch common issues before upload
- Opened your PDF at 100% zoom and checked at least 10 random pages for formatting errors
- Checked the first and last page for stray blank pages, missing content, or broken layout
- Confirmed all hyperlinks (in ebook) point to the correct URLs and are not broken
- Spell-checked the entire manuscript one final time — KDP does not catch spelling errors
- Verified that the title, subtitle, and author name in your file match what you entered in KDP — mismatches can delay publication
Frequently asked questions
What file format should I use for a KDP paperback interior?
PDF. KDP accepts DOCX as well, but PDF gives you full control over layout, fonts, and margins. A print-ready PDF with embedded fonts and correct trim dimensions is the most reliable way to get the interior you designed.
Does KDP require an ISBN?
No. KDP provides a free ISBN if you do not supply your own. The free ISBN is exclusive to Amazon and cannot be transferred or used on other platforms. If you plan to distribute through bookshops, libraries, or other retailers, you will need your own ISBN — in the UK, these are purchased from Nielsen.
What trim size should I use for a UK paperback?
The most common UK paperback size is B-format: 129 × 198 mm (5.06 × 7.81 in). This is what most fiction and narrative non-fiction is published at in the UK market. KDP supports this trim. Other popular choices include A-format (110 × 178 mm) for mass-market and Royal (156 × 234 mm) for larger non-fiction.
How do I calculate spine width?
Spine width depends on your page count and paper type. KDP provides a cover calculator that generates the exact spine width for your book. As a rough guide: white paper is approximately 0.0572 mm per page; cream paper is approximately 0.0635 mm per page. Always use KDP's calculator rather than manual maths — the figures change when KDP updates their paper stock.
What happens if my cover has no bleed?
KDP will either reject the file or add white borders around the edges where the print trimming occurs. This looks unprofessional. Always extend background colours and images 3.175 mm (0.125 in) beyond the trim line on all four outer edges.
Can I upload the same file as paperback and ebook?
No. Paperback interiors are fixed-layout PDFs with specific trim dimensions, margins, and embedded fonts. Ebooks are reflowable files (EPUB or DOCX) where the reader controls font size and screen width. You need separate files for each format. A formatting tool like Atticus can export both from a single manuscript.
About this guide
Written by Robert Prime for publishing.co.uk. Last reviewed July 2026. KDP specifications change — verify current figures on KDP's help pages before relying on them.
If you would rather have a professional handle the formatting, our KDP formatting service delivers upload-ready interiors and covers from £69.
