What is the difference between an ASIN and a GTIN?

A GTIN (such as a UPC or EAN) is a universal identifier issued by GS1 and recognised by every retailer. An ASIN is internal to Amazon and identifies a product page only within Amazon. You typically supply a GTIN, and Amazon assigns or matches an ASIN.

How do I find a product's ASIN?

The ASIN appears in the product page URL after "/dp/" and in the "Product information" section of the listing. It is a 10-character alphanumeric code.

Can two sellers share the same ASIN?

Yes. Many sellers can list offers against the same ASIN when they sell the identical product, competing for the Buy Box on that single product page.

Do I need a GTIN to create an ASIN?

In most categories, yes — Amazon asks for a product ID such as a UPC or EAN to create a new listing. Brand-registered and certain exempt products can create ASINs without a GTIN.

Glossary

ASIN

Amazon Standard Identification Number

An ASIN (Amazon Standard Identification Number) is a 10-character alphanumeric code that Amazon assigns to every distinct product in its catalogue. Unlike a GTIN, an ASIN is owned and controlled by Amazon and is unique to the Amazon ecosystem.

Last updated: June 2026

Key facts

An ASIN is a 10-character code (letters and numbers) generated and owned by Amazon, not by GS1.
Every product page on Amazon has exactly one ASIN per marketplace; many sellers can list under the same ASIN.
For books, the ASIN is usually the same as the 10-digit ISBN.
You usually supply a GTIN when creating a product, and Amazon either matches it to an existing ASIN or generates a new one.

What an ASIN is and how it is created

An ASIN identifies a product page within Amazon. It appears in the product URL and in the "Product information" section of every listing. When you create a brand-new product that does not already exist in the catalogue, Amazon generates a fresh ASIN for it; when your product already exists, you list your offer against the existing ASIN instead of creating a duplicate.

The key distinction from a GTIN is ownership. A GTIN is a universal identifier issued by GS1 and recognised by every retailer in the world. An ASIN is internal to Amazon — it has no meaning outside Amazon and cannot be used to identify the product on eBay, Kaufland, or any other channel. You can think of the GTIN as the product's global passport and the ASIN as its Amazon-only membership number.

ASINs, GTINs and catalogue matching

When you add a product in Seller Central, Amazon usually asks for a product ID such as a UPC or EAN (a GTIN). Amazon checks that GTIN against its catalogue. If a matching ASIN already exists, your offer is attached to it and you compete with other sellers on the same page for the Buy Box. If no match exists, Amazon creates a new ASIN.

This is why two sellers shipping the identical branded product end up on the same ASIN — they both supplied the same manufacturer GTIN. It is also why a private-label seller who buys their own GTINs gets their own dedicated ASIN that no competitor can list against, which is central to brand protection on Amazon.

Books are a special case: the ASIN for a printed book is normally identical to its 10-digit ISBN, because Amazon adopted ISBNs as ASINs in its early days as a bookseller.

Why ASINs matter operationally

Because the ASIN is the unit Amazon ranks, advertises, and reviews against, it is the anchor of your Amazon performance. Reviews, sales rank, sponsored-product campaigns and the Buy Box all attach to the ASIN, not to your individual offer. If your listing gets merged into the wrong ASIN, you can inherit the wrong images, reviews, or even the wrong product detail.

For multichannel sellers, keeping the relationship between your internal SKU, the product GTIN, and the Amazon ASIN clearly mapped is essential. The GTIN ties the product together across every marketplace, while the ASIN is the Amazon-specific reference you use for advertising, reporting, and FBA shipments.

Example

A product page at amazon.com/dp/B08N5WRWNW has the ASIN B08N5WRWNW. Several sellers may offer that exact item, but they all list under this one ASIN and compete for the Buy Box, while each keeps their own internal SKU and the same shared manufacturer GTIN.

Why it matters for marketplace sellers

You normally need a GTIN to create a new ASIN, so securing valid barcodes is a prerequisite for launching unique products on Amazon.
Reviews, sales rank and Buy Box eligibility attach to the ASIN, so listing under the correct one is critical to performance.
Private-label sellers who own their GTINs get exclusive ASINs that competitors cannot piggyback on, which underpins brand protection.
When syncing inventory across channels, map each ASIN back to your master SKU and GTIN to avoid mismatched or duplicated listings.