Send to Kindle error E999: what it means and how to fix it
Short answer: E999 is an "internal error" from Amazon's conversion service: the file reached Amazon, but it couldn't turn it into a Kindle book. It's almost always the file, not your Kindle or your connection. Usually it's an EPUB with missing metadata (often the language), an encoding problem or a broken internal structure. Re-saving the EPUB with Calibre or a fixer tool solves most cases.
What causes E999
When you send a document, Amazon converts it into its own format before delivery. E999 means that step failed. Common reasons:
- Missing or invalid metadata: an EPUB without a language, title or identifier in its package file.
- Encoding problems: files that don't declare UTF-8 can trip the converter, especially with accents and non-Latin text.
- Broken structure: malformed XHTML, missing files referenced by the book, or an invalid table of contents. Common in EPUBs exported by some online converters.
- Unusual content: very large images, embedded fonts the converter rejects, or heavy custom styling.
- DRM: books bought from other stores with copy protection can't be converted.
Restarting your Kindle, reinstalling the app or re-sending the same file won't help. The file has to change.
Fixes, in order
1. Re-save the EPUB with Calibre
Calibre is a free e-book manager for Windows, Mac and Linux.
- Add the EPUB to Calibre.
- Click Edit metadata and make sure the title, author and language are filled in.
- Click Convert books, set the output format to EPUB, and convert. Calibre rebuilds the file cleanly.
- Send the new EPUB (right-click → Open containing folder to find it).
2. Use a Kindle EPUB fixer
The open-source "Kindle EPUB Fix" tool adds a missing language, declares the encoding and repairs common problems that make Amazon reject EPUBs. Run the file through it, then send the fixed version.
3. Validate the EPUB
If you made the EPUB yourself (with Pages, Google Docs, Word or a script), run it through EPUBCheck, the official validator, and fix the errors it lists. A clean EPUB rarely fails.
4. Send a different format
If you have the source document, send it as DOCX or PDF instead. Amazon converts Word files very reliably. See how to send a PDF to Kindle for layout options.
5. Check size and name
Stay under 200 MB on the web uploader or 50 MB per email, and keep the file name simple (letters, numbers, spaces). Very large images inside an EPUB can be shrunk with Calibre's conversion settings.
When it can't be fixed
If the book has DRM from another store, Send to Kindle won't accept it. That's a licensing limit, not a technical bug. Buy the Kindle edition, or read it in the app of the store you bought it from.
If you were sending a web article
Web pages turned into EPUBs by quick online converters are a frequent source of E999. Leafpost builds the e-book inside your browser to the EPUB 3 standard, with title, author and language set, valid XHTML, Kindle-friendly JPEG images, a cover and a table of contents. That avoids the usual causes of E999.
FAQ
Is E999 a problem with my Amazon account?
No. If other documents arrive fine, your account and device are OK. The problem is that specific file.
I got E999 with a PDF. Now what?
It's less common with PDFs. Try sending it with the original layout instead of converting it to adjustable text. If the PDF is password-protected, remove the password with the app that created it and send it again.
Where can I see whether a document failed?
On amazon.com/sendtokindle, open "Recently sent files" to see each upload's status. For emailed files, Amazon sends the error to the sender's address.