ASIN
An ASIN (Amazon Standard Identification Number) is the 10-character code Amazon uses to identify a product in its catalog. When you publish a Kindle ebook through Kindle Direct Publishing (KDP), Amazon assigns an ASIN automatically and at no cost. Kindle ASINs mix letters and numbers and usually begin with “B0”. Each format of a book (Kindle, paperback, hardcover) gets its own ASIN, and Amazon links the formats on one product page so readers can switch between them.
ASINs only exist inside Amazon. Other retailers, distributors and libraries don’t use them, which is one reason print books also carry an ISBN.
Why it matters for indie authors
Your ASIN is the most precise way to point to your book on Amazon. You’ll use it to:
- build short links to your product page: amazon.com/dp/ followed by the ASIN
- pick the right edition when you set up Amazon Ads
- check that your ebook and paperback are linked on one page
- send advance readers and newsletter subscribers to the exact format you mean
The ASIN also anchors your book’s history. Uploading a revised manuscript or a new cover to the same title keeps the ASIN, along with the reviews and ranking attached to it. Setting the book up again as a new title creates a new ASIN that starts from zero.
Example
A cozy mystery author publishes a Kindle edition and a paperback. She finds both ASINs under “Product details” on the Amazon page and on her KDP Bookshelf. Her newsletter links use the Kindle ASIN, because most of her subscribers read on Kindle, and her website lists both formats. When she fixes a handful of typos six months later, she uploads the corrected file to the existing title, and the ebook keeps its ASIN and its reviews.
Common mistakes
- Republishing instead of updating. A new title setup means a new ASIN, so reviews and rank history don’t follow. Update the existing title instead.
- Sharing the wrong format’s ASIN. A link to the paperback sends ebook readers to the wrong page, and ads for the wrong edition waste budget.
- Treating an ASIN like an ISBN. It won’t get your book into other stores or library catalogs.
- Leaving formats unlinked. KDP usually links the ebook and paperback when the title and author name match exactly. If they still appear on separate pages, compare both listings for differences, then contact KDP support.