ASIN Codes: How They’re Different from Other Barcodes
Estimated reading time: 4 minutes
What Amazon barcodes do you actually need and how do you get them?
When selling on Amazon, it’s easy to get confused by the different barcode terms: GTIN, UPC, FNSKU, ASIN codes. This guide breaks it down so you can label your products correctly, avoid fulfillment headaches, and get credit for every sale.
What are barcodes—and why do you need them?
Barcodes are scannable digital symbols that contain key product information like batch numbers and item identifiers. They’re essential for tracking products through the supply chain—from manufacturer to warehouse to customer.
GTIN, UPC, and other common Amazon barcodes
GTIN: The global product identifier
The Global Trade Item Number (GTIN) is a global numeric barcode that identifies products. Depending on the item and where it’s sold, your GTIN could be a:
- UPC (Universal Product Code)
- EAN (European Article Number)
- ISBN (International Standard Book Number)
GTINs are requirement for listing most products on Amazon and serve as the foundation for creating ASIN numbers.
UPC: North America’s go-to barcode
The UPC barcode is the most widely used GTIN in North America. It’s a 12-digit code that helps manufacturers and retailers track inventory, manage supply chains, and identify product attributes like size or color.
When creating a product listing on Amazon, you’ll often need a UPC to start. If an FNSKU barcode isn’t required, the UPC may also be used in Amazon fulfillment centers to track your products.
Get your UPC from GS1 US to ensure it’s valid and registered to your brand.
What is an FNSKU barcode?
The FNSKU (Fulfillment Network Stock Keeping Unit) is an Amazon-specific barcode used for tracking products within Amazon fulfillment centers. It ensures that sales are credited to the correct seller—even when multiple sellers offer the same item.
Amazon will tell you if your product needs an FNSKU. If it does, you’ll receive a unique barcode after setting up your listing through Fulfilled by Amazon (FBA).
You can then:
- Print FNSKU barcode labels yourself
- Apply them to your packaging
- Or provide them to your manufacturer for direct printing
Avery offers free barcode label printing options whether you need on-demand printing at home or custom printing through Avery WePrint®.
ISBN barcodes for books
Books require a special kind of GTIN—the ISBN barcode. Used by publishers, this identifier is either 10 or 13 digits depending on the publication date. You can get yours at ISBN.org.
What are ASIN codes?
An ASIN code—short for Amazon Standard Identification Number—is Amazon’s internal product ID. It’s a unique 10-character alphanumeric code that’s created when a product is added to Amazon’s catalog.
Amazon uses the ASIN number to:
- Track inventory
- Organize product pages
- Power search results and recommendations
- Deliver product data to shoppers
You don’t create an ASIN directly. Instead, you provide a GTIN (usually a UPC, EAN, or ISBN) when listing your item, and Amazon assigns an ASIN—or connects your product to an existing one.
Think of the ASIN as Amazon’s version of a product number. It’s not something you print on packaging—it’s what Amazon uses to manage listings behind the scenes.
Barcode label printing made easy
Need help printing your barcodes? Whether you’re working with ASIN codes, Amazon barcodes, or product packaging, Avery makes it simple.
With Avery, you can:
- Use the free barcode generator to create your labels online
- Print barcode labels yourself using Avery blank label sheets
- Or let Avery WePrint handle your custom barcode label printing
More resources
Still unsure which barcode to use—or how to label your product for Amazon? Check out:
No matter which type of Amazon barcode you need, Avery has you covered.
From generating ASIN codes to printing barcode labels, we make it easy to get your products ready for sale and shipment.
