EPUB and Kindle Unlimited: What Authors Need to Know
Kindle Unlimited is Amazon's ebook subscription service. Authors in the program earn royalties based on pages read. But there's a critical trade-off: Kindle Unlimited requires KDP Select enrollment, which means exclusive distribution through Amazon — no EPUB on other retailers while you're enrolled. This guide explains the choice.
What is Kindle Unlimited?
Kindle Unlimited (KU) is a subscription service ($11.99/month in the US) that gives readers unlimited access to over 4 million ebooks. Authors who enroll earn from the KU Global Fund — a monthly pool Amazon distributes based on pages read (Kindle Edition Normalized Pages, or KENP).
In 2026, the KU royalty rate is approximately $0.0045 per KENP page read. A 300-page book fully read earns roughly $1.35 per borrow — comparable to a $2.99 sale at 70% royalty.
EPUB vs KDP format
Kindle Direct Publishing (KDP) accepts EPUB files for upload — Amazon converts them internally to its KFX format for Kindle devices. You can upload an EPUB to KDP. What you cannot do while in KDP Select is distribute that same EPUB elsewhere.
The format workflow:
- Prepare your manuscript as EPUB (or DOCX/HTML — KDP accepts multiple formats).
- Upload to KDP. Amazon converts to KFX/MOBI internally.
- If you enroll in KDP Select, you agree not to distribute the ebook content elsewhere during the 90-day enrollment period.
KDP Select exclusivity requirement
KDP Select enrollment is optional but required for Kindle Unlimited access. The exclusivity clause covers:
- All digital ebook formats of the same content
- Your own website (you cannot sell the EPUB on your own site)
- Other retailers: Apple Books, Kobo, Google Play Books, Barnes & Noble, Smashwords, Draft2Digital
- Subscription services: Scribd, Storytel
Print editions are NOT covered — you can sell a paperback through IngramSpark while in KDP Select.
Violation of the exclusivity terms can result in removal from KDP Select and loss of accumulated royalties. Amazon enforces this actively.
Going wide with EPUB instead
"Going wide" means distributing your ebook through multiple retailers and channels simultaneously — the alternative to KDP Select exclusivity.
Wide distribution channels for EPUB:
| Retailer / Aggregator | Royalty | Notes |
|---|---|---|
| Amazon KDP (without Select) | 35% or 70% | No KU — listed on Amazon but not in subscription |
| Apple Books | 70% | Direct or via Draft2Digital / Smashwords |
| Kobo Writing Life | 70% | Direct or via aggregators |
| Google Play Books | 52% | Direct partner program |
| Barnes & Noble Press | 65% | Direct or via aggregators |
| Draft2Digital | ~60% net after D2D fee | Aggregator: distributes to 15+ retailers |
| Smashwords | 60-80% depending on channel | Aggregator, now part of Draft2Digital |
| Your own site | 100% (minus payment fees) | Sell direct as EPUB via Payhip, Gumroad, etc. |
Going wide works best for authors with an established readership outside Amazon, genre fiction with international audiences (Kobo is strong in Canada/UK/Europe), and non-fiction with professional audiences who use tools other than Kindle.
Hybrid strategy
Some authors use a sequential strategy:
- Launch in KDP Select for the first 90 days to maximize launch visibility and KU borrows.
- After 90 days, opt out of KDP Select renewal and go wide with EPUB to Apple Books, Kobo, and other retailers.
This captures early Amazon momentum, then builds a diversified distribution base. The risk: readers who borrowed via KU may not purchase elsewhere; the wide audience takes time to build.
Converting your PDF manuscript to EPUB for wide distribution
If you have a manuscript in PDF format (from a layout tool like InDesign or a word processor's PDF export), convert it to EPUB before uploading to aggregators.
toolkit.bot converts PDF to EPUB3 — the format accepted by Apple Books, Kobo, and all major aggregators. The output passes EPUBCheck validation and includes correct metadata structure for retail submission.
FAQ
Can I upload an EPUB to KDP?
Yes. KDP accepts EPUB, DOCX, HTML, and MOBI. EPUB is the recommended format for preserving your formatting. Amazon converts it to KFX internally.
Does KDP Select prevent me from having a print edition?
No. The exclusivity applies to digital ebook editions only. You can distribute a paperback or hardcover through IngramSpark, Amazon KDP Print, or any other printer while enrolled in KDP Select.
What happens when my KDP Select enrollment ends?
90-day enrollments auto-renew unless you turn off auto-renew in your KDP dashboard. When enrollment ends (or you turn off auto-renew), the exclusivity requirement lifts and you can distribute the EPUB anywhere.
Is Kindle Unlimited worth it for non-fiction?
Generally less so than for fiction. KU readers skew toward genre fiction. Non-fiction authors often earn more going wide — professional and academic readers are more likely to use Apple Books or purchase directly than subscribe to KU.
Convert your PDF manuscript to distribution-ready EPUB at toolkit.bot — free, passes EPUBCheck, accepted by all major retailers.