Apple Books EPUB Requirements

To publish directly on Apple Books, prepare an EPUB, appropriate metadata, and external cover art; validate the EPUB; then submit through the Apple Books Publishing Portal. EPUB 3 is the current target, an ISBN is optional, the cover must be RGB and at least 1400 pixels on its shortest side, and Apple pays 70% ebook royalties regardless of price point.

1. EPUB requirements

Apple accepts EPUB book assets. Its current Apple Books Asset Guide supports the EPUB 3.3 specification and remains backward-compatible with previous EPUB 3 versions. For a new production workflow, generate EPUB 3 rather than building around legacy EPUB 2 behavior.

Reflowable versus fixed layout

Reflowable EPUB is the normal choice for novels, memoir, narrative nonfiction, and other text-led books. Readers can resize text, change themes, and use the book across different screen sizes.

Fixed-layout EPUB is appropriate when exact page composition is essential, such as some picture books, comics, cookbooks, and illustrated educational titles. It preserves layout but requires more specialized production and accessibility work.

Required EPUB structure

An EPUB 3 package needs a valid container, package document, manifest, spine, navigation document, content files, styles, and assets. Apple’s Asset Guide identifies title, unique ID, language, and modified date as minimum package metadata. Every file included in the archive must be declared correctly in the manifest.

Validation

Apple says every submitted EPUB must pass the most recent version of EPUBCheck. The delivery must also pass Apple’s validation, which can surface packaging, manifest, encoding, URI, metadata, media, or Apple-specific issues that a visual preview does not reveal.

Run validation on the exact file you plan to upload. A formatter’s product claim, an older successful book, or a renamed ZIP is not evidence that the current EPUB passes.

2. File size, images, fonts, and accessibility

Book file size

Apple recommends keeping books as small as practical for faster customer downloads. The general maximum is 2 GB, while books created with Pages must remain under 1 GB. Reaching the technical maximum is not a goal; optimize media without degrading the reading experience.

Interior images

The current Asset Guide allows interior images up to 5.6 million pixels. Multiply width by height to check the total. Apple recommends sRGB and responsive sizing for images in flowing books. Use HTML img elements, put presentation rules in CSS, and provide meaningful alternative text.

Fonts and scalable text

Apple recommends relative font sizing such as em or percentages rather than hard pixel values. Main text should normally inherit the reader’s base size or use 1em so customers can scale it. Only embed fonts you have the right to distribute.

Accessibility

Use semantic headings, correct reading order, navigation landmarks, descriptive alt text, usable color contrast, and accessible tables. Apple’s metadata can declare supported accessibility features. Accessibility is part of the file architecture, not a checklist added after the export is finished.

3. Apple Books cover requirements

The external marketing cover delivered beside the EPUB must be:

• a high-quality JPEG or PNG;
• in RGB color mode;
• at least 1400 pixels on the shortest side;
• sharp at its submitted dimensions, not artificially upscaled from a small source.

Apple does not publish one mandatory 1600 × 2560 or 2560 × 3840 aspect ratio for every book. Preserve the cover’s intended proportion while meeting the shortest-side minimum and quality requirements.

The marketing cover is separate from the in-book cover image that readers encounter after opening the EPUB. If the EPUB was not created in Pages, Apple says the book also needs in-book cover art that follows interior-image requirements.

4. Metadata: ISBN is optional

The most important correction to many older Apple Books checklists is simple: Apple’s current metadata guide says ISBN is optional.

A unique, permanent Vendor ID is required. If the edition has an ISBN, Apple recommends using that ISBN as the Vendor ID. If it does not, create a stable identifier you will not recycle for another edition.

Core metadata to prepare

• title and, when applicable, subtitle;
• primary author and other contributors;
• a description of at least 50 characters;
• main and secondary subject categories from a supported scheme;
• publisher name;
• original publication date;
• book language;
• the permanent Vendor ID;
• explicit-content status and age information when applicable;
• series name, number, and display wording when applicable;
• ISBN when the edition has one;
• accessibility features the file genuinely supports.

Make the title, author, language, and identifier consistent among the EPUB package, portal metadata, cover, copyright page, and any aggregator record. Inconsistent identity data creates avoidable delivery tickets and catalog confusion.

5. Account and agreement requirements

For direct publication, Apple currently asks for an Apple Account with two-factor authentication, digital rights to the books, and legal authority to sign for yourself or the publishing entity. A valid card is used during account setup.

To sell paid books, complete the appropriate agreement plus tax and banking information. Apple may also require regional compliance information. For example, sellers distributing in the European Union must assess and provide Digital Services Act trader details when applicable.

A D-U-N-S number can be supplied for an organization but Apple’s current account guide says it is not required merely to sign up for Apple Books.

6. Royalty, price, and payment

Apple Books for Authors states that directly sold ebooks earn 70% royalties at every price point. Apple also advertises no file-delivery fee, no exclusivity requirement, and no price matching.

Apple says payments are made within 45 days after the end of each month. The account still needs completed tax and banking documentation and must meet the applicable minimum-payment threshold.

If you distribute through an aggregator, Apple pays the aggregator and the aggregator pays you under its own fee, timing, and reporting model. Compare convenience, store access, metadata control, and the aggregator’s economics—not only the headline Apple rate.

7. Direct upload workflow

1. Create the account. Set up iTunes Connect for Apple Books and complete the legal entity and agreement steps.
2. Prepare the EPUB. Use a book formatter, Pages, a conversion provider, or an aggregator.
3. Validate the exact EPUB. Resolve every EPUBCheck error before delivery.
4. Prepare cover and metadata. Confirm the permanent Vendor ID and make identity fields match.
5. Submit through the Publishing Portal. Apple’s current checklist calls for the EPUB and appropriate metadata.
6. Set rights, territories, price, and release information. Complete the catalog record in iTunes Connect.
7. Review delivery tickets. A successful upload is not the same as approval. Resolve technical or content issues Apple reports.
8. Inspect the live book. Check navigation, cover, sample, description, categories, price, and reading behavior on Apple devices.

8. Common reasons an Apple Books delivery fails

• EPUBCheck or Transporter validation errors;
• files inside the EPUB that are missing from the manifest;
• invalid or unencoded characters in file paths and URIs;
• incorrect text encoding;
• missing or malformed navigation;
• metadata mismatch between the EPUB and delivery record;
• a reused or unstable Vendor ID;
• cover art below 1400 pixels on the short side, blurry, or in the wrong color mode;
• interior images beyond the supported pixel limit;
• embedded fonts without distribution rights;
• missing accessibility descriptions or broken reading order;
• an incomplete agreement, tax, banking, or regional compliance step.

Primary Apple sources

• Prepare your book
• Apple Books Asset Guide 5.3.1
• Apple Books metadata fields
• Submit your book
• Royalty and sales information
• Create an Apple Books account

Frequently asked questions