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What is an ASIN on Amazon?

An ASIN, or Amazon Standard Identification Number, is the identifier Amazon assigns to each book it lists. KDP describes it as similar to an ISBN. An eBook published on KDP without an ISBN automatically gets an ASIN, so there is nothing to buy or apply for.

What it means in practice

There is nothing to do to get one. KDP’s help page, checked on 30 October 2026, says “If you publish without an ISBN, we’ll automatically assign an ASIN for your book.” Keep it for your own records and for anywhere you need to name that exact book on Amazon.

It is Amazon’s number, so don’t expect it to stand in for an ISBN elsewhere in the book trade.

How Chapbook uses it

It doesn’t. Chapbook stops before Amazon assigns anything: the KDP listing gives you each field to paste into KDP, and you publish the book yourself.

In a real book

Cover of Slow Money by Rosa Almeida: a scored round sourdough loaf on flour in warm low light above dark type on cream, subtitle “What a family bakery taught me about pricing, patience and staying small”.
Title page. Page 1 of Slow Money.
Copyright. Page 2 of Slow Money.
Contents. Page 3 of Slow Money.
Prologue: The Second Oven. Page 4 of Slow Money.
Prologue: The Second Oven. Page 5 of Slow Money.
The First Price Rise. Page 6 of Slow Money.
The First Price Rise. Page 7 of Slow Money.
The First Price Rise. Page 8 of Slow Money.
The First Price Rise. Page 9 of Slow Money.
The Loan We Did Not Take. Page 10 of Slow Money.
The Loan We Did Not Take. Page 11 of Slow Money.
The Loan We Did Not Take. Page 12 of Slow Money.
The Loan We Did Not Take. Page 13 of Slow Money.
The Second Shop, and Why Not a Third. Page 14 of Slow Money.
The Second Shop, and Why Not a Third. Page 15 of Slow Money.
The Second Shop, and Why Not a Third. Page 16 of Slow Money.
The Second Shop, and Why Not a Third. Page 17 of Slow Money.
The Second Shop, and Why Not a Third. Page 18 of Slow Money.
Hours, and the Cost of Being Open. Page 19 of Slow Money.
Hours, and the Cost of Being Open. Page 20 of Slow Money.
Hours, and the Cost of Being Open. Page 21 of Slow Money.
Hours, and the Cost of Being Open. Page 22 of Slow Money.
The Wholesale Account We Let Go. Page 23 of Slow Money.
The Wholesale Account We Let Go. Page 24 of Slow Money.
The Wholesale Account We Let Go. Page 25 of Slow Money.
The Wholesale Account We Let Go. Page 26 of Slow Money.
Hiring Family and Paying Them Properly. Page 27 of Slow Money.
Hiring Family and Paying Them Properly. Page 28 of Slow Money.
Hiring Family and Paying Them Properly. Page 29 of Slow Money.
Hiring Family and Paying Them Properly. Page 30 of Slow Money.
What the Numbers Said Each January. Page 31 of Slow Money.
What the Numbers Said Each January. Page 32 of Slow Money.
What the Numbers Said Each January. Page 33 of Slow Money.
What the Numbers Said Each January. Page 34 of Slow Money.
Epilogue: Small on Purpose. Page 35 of Slow Money.
Epilogue: Small on Purpose. Page 36 of Slow Money.
Back cover of Slow Money: the description over the cover's artwork.
Prologue: The Second Oven 5 / 38
Slow Money, what a family bakery taught me about pricing, patience and staying small: a nonfiction book of 9,273 words and 37 pages on 6 × 9 in, generated from one brief and exported unedited. It is a sample, not a customer's book. Download the PDF (425 KB) or the EPUB (226 KB).

Sources

Last reviewed 30 October 2026

  1. Amazon KDP, “What is an ISBN and Imprint Name?”
  1. What is an ISBN? An ISBN is a 13-digit identifier for one format of a book. Who applies for one, when KDP gives one free, and where Chapbook puts yours if you have one.
  2. What is Kindle Direct Publishing (KDP)? Kindle Direct Publishing is Amazon's free self-publishing service for eBooks, paperbacks and hardcovers. What it asks for, and what Chapbook prepares for it.
  3. What is KENP on Amazon KDP? KENP, Kindle Edition Normalized Pages, is how KDP counts pages read in Kindle+. How it is measured, its per-customer cap, and how it differs from a sale.

Questions people ask

What is the difference between an ASIN and an ISBN?

An ASIN is Amazon's own number, which it assigns. An ISBN is the international book trade's identifier, which a publisher applies for. KDP eBooks don't require an ISBN; KDP paperbacks and hardcovers do.

Do I enter an ASIN in Chapbook?

No. Chapbook has no ASIN field and none of its files needs one. KDP assigns the number when you publish there.

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