Amazon has announced that effective June 28, when uploading ePub content for new books or updates to previously published content on their platform, mobi files will no longer be supported.
Scott Keeney, Westchester’s Senior Composition and Digital Production Manager, outlines what Amazon’s changes mean for publishers:
In late 2020, Amazon recommended using ePub format for publishing new titles and updating previously published titles for users who loaded mobi into Kindle Previewer (KP3). Though it did not state it in that message, it was applicable to reflowable ePubs. Over the last several months, when clients have asked, Westchester has been recommending only receiving the ePub. With Amazon disapproving of sideloading to their devices as a means to preview files, the need for a mobi for review purposes had become obsolete. We do have a few clients with their own, independent need and use cases for mobi, and we continue to create and provide the mobi for them.
Amazon has accepted ePub as an input format for at least a decade, and Westchester has always built our clients’ ePubs with Amazon Kindle compliance in mind. While Amazon did allow some variance from Kindle guidelines, by 2014 Westchester’s standard ePub was entirely compliant.
To ensure quality and functionality, Westchester conducts automated validation using EPUBCheck 4.2.5 (all ePubs), and ACE by Daisy, along with using proprietary tools. We also conduct manual spot-checking of content and items including navigation and table of content links. Quality checks are conducted by reviewing in ADE (not an endorsement, ADE simply remains the most common reading system used by our clients to check ePubs). Most titles are also reviewed in Kindle Previewer 3, and titles may be checked in other reading systems as needed. Westchester also includes some content-based items that ACE can’t check for such as properly marking context breaks (aka space breaks or scene breaks) and decorative images/ornaments. We include alt text if supplied or we have internal resources who can create alt text as one of our additional services.
Westchester has continued to evolve our ePub offerings to support market needs over the years, and has been providing Amazon-compatible ePub3 files for quite some time. We also offer a variety of services to ensure your ePub and digital products are fully accessible, including alt-text writing capabilities, tagging content, XML file creation, 508 compliance, and accessible WebPDF files.
Talk with Westchester Publishing Services about how we can help ensure your new ePub content meets accessibility and platform requirements, and ways we can update your previously published content to be in compliance with current standards.
In March, we launched the 
Our team of subject matter experts has increased to support the evolving needs of our clients. We have recently welcomed Amanda Robb, Senior Supervising Editor for Math, and Debbie Allen, Senior Supervising Editor for CTE. Additionally, Meg Overman was promoted to Senior Supervising Editor for SEL and Literacy, and Sam Tucker is our Senior Editor for Culturally Responsive Education. Visit our 
The Westchester Education Services team in the UK has also increased, to meet the expanding needs of education publishers and ed-tech companies serving the UK, EMEA and Asia Pacific markets. In January, Rebecca Durose-Croft was appointed Content Director and Curriculum Specialist, and in March, Marquita Celestine joined Westchester Education Services UK as Business Development Manager. Rebecca brings a wealth of experience from Editorial and Project Management roles at publishers including Oxford University Press, Pearson Education, Cambridge University Press, and Marshall Cavendish, while Marquita was most recently affiliated with Hodder Education and DK.
March was a very busy month for Westchester UK. In addition to the acquisition of River Editorial, we participated in the IPG (Independent Publishers Guild) inaugural International Publishing Forum, which in the absence of international fairs including London and Frankfurt, served to bring together publishers, retailers, industry experts and suppliers to participate in an international forum of meetings. We will also be exhibiting at IPG’s Virtual Spring Conference next month and look forward to connecting with you there.
There are many ways that Westchester Publishing Services supports our clients’ changing editorial and production requirements. You can 
On April 6, Westchester Publishing Services and Publishers Weekly hosted the very successful 
Words are the primary means by which our clients communicate with their customers, so we are always looking at various media that we can use to connect with them, as well as our colleagues throughout the publishing industry. During the pandemic, the absence of in-person events combined with an urgent need for timely, relevant content grew, motivating us to host more webinars of our own and to partner with others in the industry to speak with their audiences about topics that were of interest to them.
On Tuesday, March 2, the 