eBook Distribution Checklist

If you are using our eBook distribution service please read the information below as it may help prevent any delays with our distribution partners accepting your book.

Accepted file formats

The file formats we accept for distribution are listed below. If you only have Word, PDF or any other file types not listed they will need to be converted to at least one of the accepted formats before they can be distributed – for more details see our eBook conversion service for Publishers page or the eBook conversion service for Authors page.

  • Accepted reflowable formats:
    • ePUB 2 or 3
    • Mobi
  • Accepted fixed-layout formats:
    • ePUB 3
    • KF8/Mobi
    • Kindle Textbook Creator (we will need the .kpf file)
    • Kindle Comics
    • PagePerfect
    • NOOK Kids (ePIB)
    • NOOK Comics
    • iBook Author (we will need the .ibooks file)

Validation of ePUB files

All ePUB files we distribute must pass the International Digital Publishing Forum’s ePUB Validation check. The validation check is an industry-wide tool aimed at ensuring that ePUB files do not contain any coding errors which will prevent them from working properly on most popular reading systems. We cannot distribute any ePUB files that produce validation errors (although validation ‘warnings’ are acceptable but should be avoided if possible).

To check your ePUB you can upload it to http://validator.idpf.org/ if the file is 10mb or less. If the file is larger than 10mb you can download a free ePUB validation tool from http://www.pagina-online.de/produkte/epub-checker/ and use this to test your file on your computer. Although this website is in German there are English instructions towards the bottom of the page.

If your ePUB file does produce validation errors you will need to fix these before you send the file to us. If you are unable to fix the errors we do offer an ePUB validation fixing service that starts at $50/£35. Please email your files to helpdesk@ebookpartnership.com or upload them via https://wetransfer.com and we will confirm the costs based on the extent of the errors.

The IDPF validation only applies to ePUB files.


In our experience eBook files are very rarely rejected by the distribution channels due to problems with the content. However, the following issues can result in your eBook being rejected or your eBook listing being removed:

  • Spelling and grammatical errors.
  • Using copyrighted material without relevant permission.
  • Explicit or offensive content.
  • Web links to competing online retailers. For example, Apple will reject or remove eBooks which include links to Amazon.
  • Incomplete or inaccurate Table of Contents.


You can include images (colour and black & white) in your eBook files but they must adhere to the following guidelines. Please note that these guidelines are not checked by the ePUB validation tools above (and we will not test the images) so you may need to confirm the suitability with your eBook conversion provider.

  • You must have permission to use the images or be the copyright holder.
  • They must be RGB and not CMYK.
  • jpg, jpeg or png file types should be used.
  • The maximum number of pixels an image can contain is 4 million. To calculate this multiple the width in pixels by the height in pixels.
  • Images should be clear and crisp. Blurry or pixelated images may be rejected.
  • Explicit or offensive images are likely to be rejected.

Cover Images

All eBooks we distribute require a front cover image. The front cover should be included within the eBook file (with the exception of Mobi files) and also provided separately. Usually eBooks do not include a back cover.

The front cover image should follow the specifications below:

  • The title and author name must match the information you provide via our Book Info form.
  • JPG, PNG or PDF format.
  • Maximum file size of 5MB, although most covers are less than 1MB.
  • RGB not CMYK.
  • Recommended width to height ratio of 1:1.6.
  • Longest side at 2500 pixels.
  • Shortest side at least 1200 pixels.
  • No 3D or boxset images.
  • Explicit or offensive images are likely to be rejected.
  • Do not mention specific retailers on the cover, e.g. Amazon No. 1 Bestseller, as other distribution channels will reject it.
  • Do not include the price on the cover.
  • Do not include a sales or discount badge or banner.
  • Do not include a barcode.
  • Do not include any website or email addresses.

If your files follow the guidelines above you are unlikely to have any problems with your eBook being accepted by our distribution partners.

If you have any questions please visit our Support section.

 Distribution, EBook Distribution  
Total 0 Votes

Tell us how can we improve this post?

+ = Verify Human or Spambot ?