The thresholds, with the numbers. Every figure on this page comes from Amazon's or Ingram's own documentation, not from a blog, and each one is linked at the bottom.
Most pages that answer this question say "make sure your margins are big enough" and leave it there. That is not an answer. A platform either accepts a file or it does not, and the line it draws is a number. Here are the numbers.
If something below does not match what you see in your own KDP account, trust your account: Amazon varies requirements by ink, paper and trim size, and the dates on this page tell you how old these readings are.
This is the most common reason a print interior is refused, and the one authors are least aware of. A font that is not embedded does not travel with the file. The printer substitutes whatever it has, and your layout moves: line breaks change, pages reflow, and the book you approved is not the book that prints.
There is a second trap. A font whose licence does not allow commercial embedding will be refused even when you did everything right in the export dialog. That is a licensing problem, not a software problem, and it is solved by changing the font.
The outside margins are a fixed number. The inside margin, the one at the fold, is not: it grows with the thickness of the book, because a thick book curves away from you at the spine and swallows the inner edge of the page.
| Page count | Inside (gutter) | Outside, no bleed | Outside, with bleed |
|---|---|---|---|
| 24 to 150 | 0.375 in (9.6 mm) | 0.25 in (6.4 mm) | 0.375 in (9.6 mm) |
| 151 to 300 | 0.5 in (12.7 mm) | 0.25 in (6.4 mm) | 0.375 in (9.6 mm) |
| 301 to 500 | 0.625 in (15.9 mm) | 0.25 in (6.4 mm) | 0.375 in (9.6 mm) |
| 501 to 700 | 0.75 in (19.1 mm) | 0.25 in (6.4 mm) | 0.375 in (9.6 mm) |
| 701 to 828 | 0.875 in (22.3 mm) | 0.25 in (6.4 mm) | 0.375 in (9.6 mm) |
Top and bottom margins follow the outside figures. And the measurement is not kind: it covers every text block on the page, which means your running heads and your page numbers too. A folio sitting 5.8 mm from the top edge fails, even though the body text is comfortably inside.
Two details that catch people. Italic characters lean past the margin box and can trip the check on their own. And changing your trim size later reflows the text, which changes the page count, which can move you into the next gutter band. Recheck the margins after any size change.
If nothing on your pages touches the edge, you do not need bleed and this section does not apply. If an image or a block of colour runs off the page, it has to run off further than the page, because the trimming blade is not surgical.
And as the table above shows, choosing bleed raises your outside margin minimum from 0.25 in to 0.375 in. People add a full bleed image late in the process and fail a margin check they had already passed.
Resolution is not a property of the image file. It is the relationship between the pixels in the file and the size it is printed at. The same photograph is 300 dpi in a postcard and 75 dpi across a page.
On screen everything looks sharp, because your screen is around 100 dpi and flatters everything. The page is the test, not the monitor.
| Minimum | 24 pages |
| Maximum | Depends on ink and paper. A 6 x 9 in book in black ink on white paper allows 24 to 828 pages; standard colour allows 72 to 600. |
| Parity | The count is rounded up to an even number, because a printed leaf has two sides. |
| Blank pages | No more than 4 consecutive blanks at the start or in the middle, no more than 10 at the end. |
| Spine text | Not possible below 79 pages: the spine is too narrow to print on. |
Page numbers must run in sequence, and they must land on the right side: in a left to right book, even numbers on left pages and odd on right. In a right to left book, the reverse. This is one of the quiet ways a translated book goes wrong, because the pagination was built for the original direction and nobody flipped it.
The page size of your PDF must equal your chosen trim size, plus bleed if you used it. Not close to it. Equal.
The spread trap catches designers more than authors. A book designed as facing pages exports naturally as spreads, and the result is a file where every page is twice the width it should be. It is a two minute fix and a guaranteed rejection.
Unflattened transparency is the one that produces the strangest failures: the file uploads, the preview looks right, and the printed copy has a grey box where a drop shadow used to be. Flatten before export, not after.
This section exists because the answer surprises almost everybody, and because the usual advice online is simply wrong.
An Arabic paperback therefore has to be produced somewhere else. IngramSpark is the usual route. Plan that before the layout is built, not after, because the trim sizes and the margin rules are not identical.
Arabic is also absent from the list of languages that receive Amazon's Enhanced Typesetting, the layer that improves justification and line breaking on Kindle. An Arabic Kindle book does not get it.
And for the ebook itself, one missing attribute is enough to be refused. See the next section.
A print interior and an ebook fail for different reasons. The ones worth knowing:
An EPUB in Arabic, Hebrew or Persian must declare its direction in the package file:
page-progression-direction="rtl" on the spine element. Without it the pages
turn the wrong way, the cover lands at the back of the book, and the upload is rejected.
Calibre does not add it. InDesign at default settings does not add it. Online converters
do not add it. It is the single most common reason an Arabic ebook is refused.
An EPUB is a ZIP with rules. The first entry must be a file named mimetype,
stored uncompressed. If it is missing, compressed, or not first, strict validators reject
the book before they look at a single page.
Web browsers forgive an unclosed tag. An EPUB reader does not: the pages must be strict XHTML. One unclosed tag in one chapter can fail the whole file.
A book has to stand on its own. An image or stylesheet pulled from a website disappears the moment the reader is offline, and several distributors refuse remote resources outright.
The package file lists everything the book contains. When that list names a chapter, an image or a font that is not actually inside the archive, you get blank pages and broken images rather than an error message.
Having a cover image inside the file is not the same as telling the reading system which image is the cover. Without that declaration, your book shows a grey rectangle in the reader's library.
Send the file and you get a written report: every point above, checked on your actual pages, in plain language, with the page numbers where each problem sits. No charge, no obligation, and no account to create.
Your file is deleted once the report is sent. It is not stored, not reused, and not shown to anyone. If your manuscript is unpublished, that matters, and it should.