Last reviewed by Robert Prime, 28 October 2026.
Quick Answer: To format a book for KDP you need different files for each format. Paperback: a print-ready PDF at your trim size, with an inside (gutter) margin that grows with page count (KDP’s minimum is 0.375 in for 24–150 pages, rising to 0.875 in for 701–828), plus a separate cover file. Kindle: a reflowable file, which KDP accepts as Word (DOC/DOCX), EPUB or Kindle Create’s KPF. You can build both in Word, Kindle Create, Atticus or Vellum, or pay a formatter. Amazon’s figures checked 28 October 2026.
This page helps you choose a route and covers both formats. For the detail of one route, see Word to KDP, step by step, how to create a paperback interior for KDP or how to format an ebook for Kindle.
Would you rather someone else did it? Our book formatting services UK start at £69, VAT included, with files back in 24 hours.
Table of Contents
- Paperback and Kindle need different files
- Step-by-Step Guide to Formatting Your Book for KDP
- Formatting choices for UK authors
- KDP formatting mistakes that cause rejections
- Formatting tools compared
- What it costs
- Frequently Asked Questions
Paperback and Kindle need different files
Formatting a book for Kindle Direct Publishing (KDP) is often the most technical and frustrating part of self-publishing, especially for UK authors who face specific market nuances that many US-centric guides overlook. When I wrote my own book, Google. Panic. Repeat., I quickly realised that writing was the easy part. Preparing a KDP-compliant file that looks professional both in print and as an ebook was a completely different beast. Despite my technical background, I spent countless hours wrestling with margins, fonts, and file types — Google. Panic. Repeat.
KDP requires precise formatting to ensure your book appears exactly as intended on a myriad of devices and in print. This includes understanding concepts like trim size, bleed, margins, and the differences between EPUB, MOBI, and PDF files. Since KDP is a global platform, UK authors must also be mindful of ISBN registration through Nielsen, VAT considerations, and pricing strategies relevant to the UK market.
Before you start, ensure you have:
- A finalised manuscript in a clean, editable format (preferably Word DOCX or Google Docs).
- Clarity on your book’s physical dimensions (KDP supports many trim sizes but 5"x8" and 6"x9" are popular).
- A UK-registered ISBN if you want to maintain control over your publishing imprint (free KDP ISBNs show “Independently published”).
- Access to professional formatting tools or services if you don’t want to build the formatting yourself.
- A clear budget that includes not only formatting but also cover design, ISBNs, and VAT-related tax implications.
- Awareness of market expectations in the UK, including print quality standards and retail pricing norms.
Note: Decide on your ISBN before you publish. Amazon says its free ISBNs “cannot be used to publish outside of KDP”, so moving the book later means a new ISBN.
Experience insight: I consult for a billion-pound business that was struggling with the exact same formatting issues—it was literally stopping them from scaling their back catalogue. This shows even large publishers don’t have it all figured out.
Step-by-Step Guide to Formatting Your Book for KDP
1. Choose Your Trim Size and Page Setup
Your book’s trim size determines its physical dimensions and impacts layout decisions. Popular UK self-published sizes are 5"x8" (127mm x 203mm) or 6"x9" (152mm x 229mm). Setting the right trim size early saves headaches later.
In Microsoft Word:
- Go to Layout > Size > More Paper Sizes.
- Enter your desired width and height in millimetres or inches.
- Click OK.
For UK authors, I recommend using millimetres since the UK publishing industry standardises on metric measurements, plus it’s easier to communicate with designers and printers locally.
Set margins to accommodate the binding:
- Go to Layout > Margins > Custom Margins.
- Use at least 12.7mm (0.5") for outside margins and increase the inside margin (gutter) to 19mm (0.75") or more to allow for the binding.
Pro tip: For books with many pages (over 150), increase the inside margin further to avoid text disappearing into the spine. For example, 22mm for 200+ pages is safer.
2. Format Your Paragraph Styles
Fiction and non-fiction have different conventions:
- Fiction: Use first-line indents (about 7.5mm or 0.3") without extra spacing between paragraphs to keep the flow natural.
- Non-fiction: Often uses block paragraphs with spacing between paragraphs and no indent, making lists and sections clearer.
In Word:
- Highlight your paragraphs, right-click and select Paragraph.
- Under Indentation, set Special: First line to 7.5mm (0.3").
- Under Spacing, set After to 0 for fiction or 6-8pt for non-fiction.
Avoid manual spacing with Enter keys — use styles for consistency. Create and modify your own paragraph styles named “Body Text – Fiction” or “Body Text – Non-fiction” for easy reuse.
3. Choose Appropriate Fonts
KDP supports most standard fonts, but avoid decorative or overly stylised fonts like Papyrus, Bleeding Cowboys, or anything that hurts readability. Reliable choices include Garamond, Georgia, Times New Roman, or Arial for body text.
Font size should be between 10pt and 12pt, depending on your genre and target audience. For children’s books or older readers, 12pt or larger is advisable.
UK-specific note: UK readers often expect serif fonts for literary fiction and non-fiction, as they’re easier on the eye in print. On Kindle devices, sans-serif fonts like Arial or Verdana can work better for screen readability.
4. Insert Page Numbers and Headers/Footers
Page numbers are essential for print books but not for Kindle ebooks.
In Word:
- Go to Insert > Page Number.
- Choose bottom centre or bottom outside corners for print.
- Use Different Odd & Even Pages under Design > Options for professional layout.
Avoid page numbers on chapter opening pages — use Section Breaks:
- At the start of each chapter, insert a Next Page Section Break via Layout > Breaks > Section Breaks > Next Page.
- In the header/footer, unlink from previous section to remove page numbers on chapter starts.
5. Prepare Chapter Titles and Table of Contents (TOC)
Use Heading 1 styles for chapter titles. This allows Word to generate a clickable TOC.
For print books, insert the TOC after your front matter:
- Go to References > Table of Contents and choose an automatic style.
- Update the TOC after any edits by right-clicking and selecting Update Field.
For Kindle ebooks, KDP generates navigation based on your headings, but double-check with preview tools and on actual devices.
Pro tip: Use Heading 2 and Heading 3 sparingly for sub-sections to maintain clean navigation.
6. Handle Images and Graphics Carefully
Images must be high resolution (at least 300 dpi) for print. Insert images with Inline with Text wrapping to avoid layout issues.
For print books requiring bleed (images extending beyond the page edge), you need to increase page size slightly — for example, add 3mm bleed on all sides — and set the bleed margins in your PDF export. KDP requires a trimmed size plus bleed in the PDF.
UK tip: Use CMYK colour mode for print covers, as UK printers often expect this. KDP accepts RGB, but for local print runs or expanded distribution, CMYK ensures better colour matching.
7. Exporting Your File
For Kindle ebooks:
- Save or export your manuscript as .docx or .epub.
- KDP accepts Word DOCX natively and converts it to Kindle format.
- For better control, you can convert to EPUB using tools like Calibre or Vellum (Mac only).
For print:
- Export a PDF with embedded fonts and correct trim size/bleed.
- In Word, go to File > Save As > PDF, then select Options and leave ISO 19005-1 compliant (PDF/A) unticked — KDP doesn’t require PDF/A and it can strip colour profiles or cause font issues; just make sure fonts are embedded in a standard high-quality PDF.
- Ensure “Bitmap text when fonts may not be embedded” is unchecked to keep text crisp.
8. Validate and Preview Your Files
Use KDP’s Previewer tool to see how your book appears on various devices and in print. Look out for:
- Orphan or widow lines (single lines at top or bottom of pages).
- Incorrect page breaks or chapter breaks.
- Font or image glitches (missing fonts or low-res images).
Fix issues by adjusting your source file and re-uploading. For print, order a proof copy from KDP to check physical quality before finalising.
Experience insight: When I was formatting Google. Panic. Repeat., I spent hours on previewing and fixing tiny layout issues that no automated tool caught. This step is crucial and often overlooked.
Formatting choices for UK authors
Trim size. UK paperbacks are often smaller than the American 6 × 9 in. KDP’s list includes 5.06 × 7.81 in (12.85 × 19.84 cm) and 5 × 8 in (12.7 × 20.32 cm), and it also offers A4, 8.27 × 11.69 in (21 × 29.7 cm), for black-ink books of 24 to 780 pages on white paper (A4 is not offered with standard colour ink). Source: KDP trim size, bleed and margins, read 28 October 2026. Which size suits your genre: standard book sizes in the UK.
Margins in millimetres. KDP gives its minimums in both units. The inside margin is 9.6 mm for 24–150 pages, 12.7 mm for 151–300, 15.9 mm for 301–500, 19.1 mm for 501–700 and 22.3 mm for 701–828. Outside margins are at least 6.4 mm, or 9.6 mm with bleed. Setting a margin exactly at the minimum leaves no room for error, so add a few millimetres.
Word set up for the UK starts on A4. If you format in Word, change the page size to your trim size before you style anything, or every page break will move later. Word to KDP shows the clicks.
British punctuation and spelling. Decide on single or double quotation marks and UK or US spelling, and apply them through the whole file before formatting. Changing them after layout re-flows the book.
ISBN on the copyright page. Use the ISBN for that format: each format has its own. Free KDP ISBN or your own from Nielsen: ISBN requirements in the UK.
Your genre. Layout conventions change by genre. We have separate guides to formatting a thriller, a science fiction novel, a self-help book and a poetry collection.
KDP formatting mistakes that cause rejections
The Freelancer Trap
Before building publishing.co.uk, I hired a formatter for £130 who delivered a shoddy job: inconsistent margins, missing page numbers, and poor chapter breaks. Then I tried Fiverr — same story. These cheap gigs often fail to deliver KDP-compliant files, causing costly delays and frustration.
Avoid this trap: Vet freelancers carefully, ask for samples, and confirm KDP experience. Alternatively, use automated UK-focused services that understand the nuances of the UK market.
Formatting Without Styles
Many authors manually format their manuscript with spaces and tabs instead of using paragraph styles. This leads to inconsistent layout and problems during file conversion.
Fix: Learn and use Word’s Styles feature religiously. It’s your formatting backbone and makes fixes and conversions smoother.
Ignoring Bleed and Margins
Not accounting for bleed on print covers or setting insufficient margins causes content to be cut off or look cramped in print.
Tip: Always add a 3mm bleed on covers and ensure inside margins are wide enough for binding. Use KDP’s templates as a guide.
Using Unsupported Fonts
Fonts like Papyrus or Comic Sans kill credibility and readability. Stay professional with classic serif or sans-serif fonts.
Overlooking UK Pricing and ISBNs
Using a free KDP ISBN might seem like a shortcut but gives Amazon control over your title’s metadata, which can limit your brand’s future potential. Similarly, ignoring UK VAT and pricing nuances leads to incorrect royalties and customer confusion.
Poor Image Resolution
Low-res images print pixelated, damaging your book’s quality and reviews.
Always use 300 dpi or higher for print images. For ebooks, 72 dpi is acceptable but higher res is better.
Formatting tools compared
Software
- Microsoft Word: The industry standard for manuscript formatting; use Layout > Margins > Custom Margins for precise control.
- Adobe InDesign: Professional layout software for advanced users seeking full control.
- Scrivener: Excellent for writing organisation but requires export to Word or EPUB for formatting.
- Calibre: Useful for converting ebooks but limited for print formatting.
- Kindle Previewer: Essential for checking ebook appearance on devices and validating files.
- Affinity Publisher: A cost-effective alternative to InDesign for professional layout, gaining traction among UK indie authors.
ISBNs and Barcodes
- Purchase UK ISBNs via Nielsen.
- Generate EAN-13 barcodes for print covers once you have your ISBN. Many barcode services offer UK-specific barcodes.
- Free ISBNs from KDP do not require barcodes.
Publishing.co.uk Formatting Service
For UK authors overwhelmed by formatting or lacking time, automated services like publishing.co.uk offer tailored solutions ensuring KDP compliance without the headaches. This allows authors to focus on writing and marketing.
Author insight: I built publishing.co.uk after my own painful formatting experience to provide UK authors with a no-nonsense, reliable solution that respects UK market standards.
What it costs
Publishing on KDP is free. What costs money is the help you buy: editing, a cover, formatting, ISBNs, proof copies. Every part is priced, with sources and dates, in how much it costs to self-publish a book in the UK, which also has a calculator for your own book.
Frequently Asked Questions
What is the most common mistake UK authors make with how to format a book for KDP?
The most frequent error is underestimating the complexity of print margins and bleed, combined with not checking the file in KDP’s previewer and a printed proof. These lead to avoidable rejections and errors in the finished book.
How much does formatting a book for KDP cost in the UK?
Costs vary widely. DIY is free but time-consuming and risky. Freelancers can charge £130 or more, often with mixed results. UK-focused services like publishing.co.uk are flat-rate: £69 print interior, £119 print plus Kindle, £179 complete, £219 picture book. For a like-for-like comparison of every UK route at real prices, see book formatters in the UK compared.
What tools are best for UK authors to format books for KDP?
Microsoft Word remains the standard for manuscript formatting. Adobe InDesign is powerful but has a steep learning curve. Kindle Previewer is essential for validation. For hassle-free, UK-specific compliance, services like publishing.co.uk are increasingly popular.
How long does the formatting process usually take?
Self-formatting can take days or weeks depending on complexity and experience. Professional services can reduce this to a few days or even hours, letting you focus on writing and marketing.
Should I buy my own ISBN or use KDP’s free one?
If you want full control over your book’s metadata, branding, and wider UK distribution, buy your own ISBN from Nielsen. Free KDP ISBNs are fine for quick Amazon-only publishing but limit future options.
What UK-specific formatting details should I watch out for?
Use metric measurements for trim sizes and margins, add 3mm bleed on print covers, price in £ with VAT considerations, and ensure your cover spine width is calculated correctly for UK paper types. Also, avoid cheap formatting shortcuts that don’t respect UK standards.
