Amazon
Selling products through Amazon requires a GTIN
Amazon requires GS1 barcodes for your products. Initially, you'll need a Global Trade Item Number (GTIN) to identify the product for an Amazon listing. GS1 Association Greece is the sole source for the issuing of valid GTINs and EAN/UPC barcodes.
Amazon verifies the authenticity of GTINs through GS1 registries. If you do use a GS1 barcode for Amazon, make sure it’s consistent with GS1 standards. Inconsistencies can lead to charge backs and other problems. For more information visit Amazon Seller Central.
Getting your codes from an unauthorized source may cause loss to the business, resulting in possible recoding or repackaging of products or even their rejection from your business partners.
Listing your products on Amazon
When you upload a product on Amazon, the first attribute you’re asked for is the product ID. This is the unique GTIN that is provided to you by GS1 (if you are distributing/selling someone else’s products, you should use their barcodes).
Amazon allows you one of the following options considering the type of code UPC, EAN or GTIN, which is related to the number of digits of the code:
EAN | Amazon’s terminology is slightly different to the GS1 standard. So, for a GTIN 13, which is what you’ll be allocated from GS1 Association Greece, you need to select EAN. |
UPC | Should be selected if you’ve been allocated a GTIN-12. It is unlikely to have to make use of this code since it is an older practice of few retailers in the USA. |
GTIN | Should be selected if you’re selling a case or a box of products that has a GTIN-14 assigned to it, for example a case including 6 products that are usually sold separately. |

The EAN code is the primary key we use to match products and ensures that we present complete and detailed information to our customers – the EAN code is mandatory information we request, it is essential.
Nicolli de Souza, Amazon
Why do I need a GTIN for selling online?
Selling a product on large e-commerce markets such as a marketplace requires a unique way of identifying products. The GS1 GTIN is a recognised international standard and is accepted globally.
Even though there is no scanning of the products, as at the points of sale, the number behind the barcode known as the GTIN is necessary to uniquely identify the product.
Why should I choose GS1?
The greatest advantage of GS1 barcodes is that they are accepted globally. Once you have a GS1 GTIN, you can use the same number to expand your business seamlessly to other e-commerce sites, online marketplaces and physical retail stores. Your GTIN is unique within the GS1 system so your product can’t be confused with similar ones. A GTIN provides better visibility to your products online.
Retailers often verify the authenticity of the barcodes before allowing you to sell in store or online, by checking the GS1 registries.
FAQs
This issue commonly arises from sellers selecting an incorrect product ID.
Amazon allows you one of the following options considering the type of code UPC, EAN or GTIN, which is connected to the number of digits of the code:
EAN - Amazon’s terminology is slightly different to the GS1 standard. So, for a GTIN 13, which is what you’ll be allocated from GS1 Association Greece, you need to select EAN.
UPC - Should be selected if you’ve been allocated a GTIN-12. It is unlikely to have to make use of this code since it is an older practice of few retailers in the USA.
GTIN - Should be selected if you’re selling a case or a box of products that has a GTIN-14 assigned to it, for example a case including 6 products that are usually sold separately.
For more information contact Amazon Seller Support.

I need GTINs for my products
The uniqueness and validity of GTINs and GS1 barcodes is ensured only when these are issued by GS1 national associations, which consist the only reliable source for their management globally.
GS1 Association Greece is an independent, not-for-profit organisation, member of the global Organisation. It is the only legal and authorized carrier in Greece to issue and manage GS1 prefixes 520 and 521.