Significance of Amazon ASIN for Your Business

An ASIN (Amazon Standard Identification Number) is the 10-character code Amazon uses to identify each product in its catalog. You don't create it yourself: Amazon assigns a new ASIN when a new product detail page is created. If several sellers offer the same item, their offers are grouped on that one detail page under its ASIN. You'll see the code on the product page and in your Seller Central inventory.

How an ASIN works

The code is a mix of letters and numbers, and for most products it starts with "B". Books are the exception: their ASIN is the 10-digit ISBN. When a customer searches or browses, Amazon matches the query to ASINs to pull up the right product, so the code sits at the center of how the catalog is indexed and searched.

If you sell in more than one Amazon country store, such as Amazon.com and Amazon.co.uk, look up the ASIN in each store before you list. Don't assume the code carries over.

When you match an existing ASIN vs. create a new listing

Search Amazon's catalog for your product first. If the exact product is already there, you don't build a new listing. You add your offer to the existing product detail page, matching it by its ASIN or another product ID. If the product isn't in the catalog yet, you create a new listing, and Amazon assigns its ASIN when that detail page is created.

Sizes and colors work a little differently. Each size or color of a product gets its own ASIN, called a child. A parent ties those children together, so a shopper picks a size or color on one detail page instead of finding a separate page for each. Amazon calls this a variation relationship.

Why it matters for your store

The ASIN is what your inventory, reporting, and ad campaigns all hang off of. Match to a near-duplicate listing instead of the exact product and your stock, reviews, and sales data end up attached to someone else's page. Confirm the ASIN matches your exact product, down to size and color, before you list.

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