# 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.

Last reviewed 30 October 2026. Web page: https://chapbook.ink/glossary/asin/

## 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](/glossary/isbn/) elsewhere in the book trade.

## How Chapbook uses it

It doesn't. Chapbook stops before Amazon assigns anything: the [KDP listing](/manual/launch-and-export/#copy-the-kdp-listing) gives you each field to paste into KDP, and you publish the book yourself.

## Made with Chapbook: Slow Money

Slow Money: What a family bakery taught me about pricing, patience and staying small, by Rosa Almeida. Nonfiction book, 9,273 words, 37 pages. A sample generated from one brief and exported unedited; it is not a customer's book. Read every page: https://chapbook.ink/examples/bakery/

The brief:

> Twenty years of running a two-shop family bakery: the decisions about price, growth and hours that kept it small and solvent. Promise: A clear-eyed account of how a small business stays small on purpose, with the numbers and rules of thumb that made it work. Reader: A small-business owner weighing a second location, a price rise, or a loan. Voice: First person, narrative chapters that each end with what the author would tell a friend; a fictional family, bakery and town; no invented statistics beyond the bakery's own illustrative numbers.

The outline the planner proposed:

1. Prologue: The Second Oven (585 words)
2. The First Price Rise (1,250 words)
3. The Loan We Did Not Take (1,101 words)
4. The Second Shop, and Why Not a Third (1,186 words)
5. Hours, and the Cost of Being Open (1,085 words)
6. The Wholesale Account We Let Go (1,142 words)
7. Hiring Family and Paying Them Properly (1,216 words)
8. What the Numbers Said Each January (1,179 words)
9. Epilogue: Small on Purpose (478 words)

## Questions

### 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.

## Sources

- [Amazon KDP, “What is an ISBN and Imprint Name?”](https://kdp.amazon.com/en_US/help/topic/G7DMSKCM9DVS65TC)