Here’s the scenario: you’ve got yourself a trending product to sell on Amazon, found the right manufacturer and set up your Amazon Seller account. All that’s left is to finally list your product on Amazon.
Hold on. What’s this? You need an External Product ID to post a listing? And what in the world is an ASIN, GTC and UPC number?
You may have already clicked the “I don’t have a Product ID” checkbox at this point, but Amazon then asks that you apply for a GTIN exemption, opening another can of worms.
If this situation sounds familiar, don’t fret. This guide will explain what each product ID means, which ones you need and how to get them.
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What is an Amazon Product ID?
For sellers to list a product on its online marketplace, Amazon needs a product ID. It is a unique identifier number used to identify and track commercial products and generally comes in the form of a barcode. The person or business that manufactures a product will need a product identifier for each item they produce.
These product IDs all fall under one banner: a GTIN. Yes, that is one of the options you can pick to list your product. So, let’s get into each one and find out what they mean.
What is a GTIN number?
A Global Trade Item Number (GTIN) is a 14-digit universally recognised unique identifier number for a product. It’s the number you see just below a barcode on nearly every commercial trade item around the globe and are used to search for product information on a database for international trade.
These numbers were developed by an international organisation called Global Standards 1 (GS1) to sell and track products to buyers.
A GTIN number can be used to identify your product on Amazon, but it can be used on other marketplaces, too.
What is an ASIN number?
Amazon Standard Identification Number (ASIN) is a ten-digit alphanumeric unique code that identifies products on Amazon. When sellers create a new product in Amazon’s product catalog, the product is given a unique ASIN number.
This helps Amazon users identify products on Amazon easily. Nearly every product in Amazon’s catalogue has an ASIN number, except for books, which have an International Standard Book Number (ISBN). The number should look like this: “B0BRWYFGYT.”
An ASIN is essential in order to sell a product on Amazon. Sellers can either create a new ASIN or use an existing one when putting up a product to sell.

What is an FNSKU number?
A Fulfilment Network Stock Keeping Unit (FNSKU), or Amazon barcode, is another Amazon-specific unique identifier number that is used to identify items from Fulfilment By Amazon (FBA) sellers. It makes it easier for the company to track your inventory and ensure the right seller is getting credit for a sale.
An FNSKU is required to be labelled on each product before being sent to a fulfillment center, which Amazon provides once you’ve set your product to FBA. There are three ways to do this: print the FNSKU and label the product yourself, send the FNSKU to your supplier to label your products, or have Amazon label each item for a fee (around $0.55 per item).
It’s easier to have your supplier label each product before they are sent out, but depending on your circumstance, you can pay Amazon to do the legwork for you. Although, this can really cut your budget if you have many items.
What is a UPC number?
Universal Product Code (UPC) is a 12-digit unique identifier barcode number that is a type of GTIN. While “universal” is in the name, a UPC is used for commercial products in North America. It’s another barcode number used to identify and track items, mainly in Canada and the US.
What is an EAN number?
European Article Number (EAN), also known as an International Article Number, is a 13-digit unique identifier number and type of GTIN used for products sold in European markets and is compatible with an EAN.
What is a JAN number?
Japan Article Number (JAN), also known as an International Article Number, is a 13-digit unique identifier number and type of GTIN used for products sold in Japan markets and is compatible with an EAN. Starting to make sense now, eh?
What is an ISBN number?
International Standard Book Number (ISBN) is a 13-digit unique identifier number used for books. If you’re selling a book on Amazon, an ISBN will need to be provided, and can be received from the International ISBN Agency.
What is a GCID number?
Global Catalog Identifier (GCIN) is a product ID number for items that do not have a GTIN number (whether it be a UPC or ISBN). This is generated by Amazon when sellers apply for a GTIN Exemption.
Wondering how to get a GTIN exemption? If a manufacturer or publisher doesn’t provide a GTIN, Amazon sellers can apply for an exemption and get a GCID. This is mainly for private label sellers or handmade products, but users can also apply for a GCIN exemption if they are selling parts for a product or bundled packs.
What Product ID should I choose?
Depending on the region you’re selling in and the Amazon product category you’re selling under, you will require a different type of GTIN.
For example, if you’re selling a product in the US, you will likely need a UPC barcode. That also goes for products sold in Europe and Japan. There are also requirements depending on the category. As another example, Amazon states, “major brands require a UPC but exemptions may be requested only for products that are private label, handcrafted, or both,” if you’re selling under the Home & Garden category.
Generally, many sellers will need a UPC to sell a product (if you’re selling in the US). However, it’s easy to figure out what product ID you require by heading to Amazon’s Product ID support page.
How do I get a Product ID?
If you’re creating a listing for a new product on Amazon, you will need a GTIN. You can get a GTIN (barcode), including the different types available, by simply heading to the GS1 website. It’s the only place Amazon approves of GTINs.
You will have to bar for a GTIN for each unique product you sell. For example, if you’re selling a shirt, you’ll need a GTIN for all the shirts of the same type you’re selling.
One GTIN costs $30, but the more you buy the cheaper it gets. If you’re just starting out as an Amazon seller, it’s best to sell one product so you only need one GTIN.
As mentioned previously, you can apply for a GTIN exemption if you’re selling under a private label and your manufacturer doesn’t supply a GTIN, or if you’re selling product parts. Amazon states that giving these out are rare, but it’s worth giving it a go.
If you’re reselling a branded product that’s already listed on Amazon, you may need to Appy to Sell the product. You can check this by searching for a product when adding a product and selecting Show limitations.

Do I need multiple Product IDs for variations?
The short answer: yes.
You will need a GTIN for each product variation if your product comes in different sizes and colours.
As an example, if you’re selling a shirt in a medium size and the same shirt in a small size, you will need two GTINs for these products. The same goes for a shirt that comes in red and one that comes in blue. And if these different coloured shirts also come in various sizes, these will also need individual GTINs.
It can get quite expensive if you’re buying GTINs for multiple product variations, especially if you’re kicking off your business. Keeping it simple will cut down costs a ton, and we recommend building up your product and brand if you’re starting to sell on Amazon.