Change in Multi-Format eBook Files:
Replacing Amazon's MOBI with EPUB
The MOBI format will no longer be available for download as of August 18, 2022 for any past purchase of a multi-format eBook here on the Microsoft Press Store website.
Amazon has announced the retirement of its proprietary MOBI file format for eBooks, and a transition to the EPUB format for use on Kindle devices and apps. As of August 2022, you will no longer be able to send the MOBI file format to Kindles or the Kindle app using the Send to Kindle service. The MOBI file format no longer supports the newest document features, while the EPUB format is updated and accepted by Kindle devices.
Any MOBI files you have already sent to your Kindle will not be affected by this change. However, the downloadable multi-format eBook files available on your Microsoft Press Store account will no longer include the MOBI format; those links will be removed on August 18, 2022. The EPUB and PDF links will remain. Purchases of future multi-format eBook files on microsoftpressstore.com after August 18 will include the EPUB and PDF formats, but will no longer include MOBI.
This change does not mean any loss in content from your purchase, as the EPUB file already included with your purchase still contains all the same content, and may be used on the same devices and apps as the MOBI format was. Please visit your account and download any MOBI files you wish to retain, before August 18. After August 18, please use the EPUB format for viewing on Kindle apps and devices.
Need help? You may also view Amazon's Help Page for information on sending content to Kindle devices and apps, and contact Amazon Digital Services and Device Support for assistance with loading the EPUB format.