Ultimate guide to GTINs, EANs and UPCs for Amazon, eBay & Google

By Chris Dawson February 21, 2016 - 7:10 pm

GTINOnline sellers are being required to add product identifiers to their listings on Amazon, or Google Shopping. These usually take the form of a Brand, Manufacturer Part Number (MPN) or an EAN (European Article Number) or UPC (Universal Product Code). This is a new requirement for online sellers – and it can be a tedious task for them to update all of their listings.

Product identification forms a vital part of any businesses supply chain. We think it’s important for you to understand the basics of why this is happening, so DaytodayeBay have created these FAQs in collaboration with GS1 UK. GS1 are the not-for-profit organisation that represents the UK in administering and maintaining the global GS1 system of supply chain standards– which includes the numbering system we’re now required to use for identifying products online.

What is a barcode?

A barcode is the image you’ll recognise from most products that you see every day. The pattern of light and dark areas is a form of data carrier that allows for a machine to read a number, which identifies the product, automatically.

What is a GTIN?

Global Trade Item Number (GTIN) –The name given to the number that uniquely identifies a product. Is 12 digits in North America, but it’s usually 13 digits long in the rest of the world, or occasionally 8 digits (for very small products).

EAN BarcodeWhat is an EAN?

European Article Number (EAN) – The name given to the standard barcode image that represents the 13 digit GTIN on most products you buy in shops in the UK and globally, except for North America.

UPC BarcodeWhat is a UPC?

Universal Product Code (UPC) – The name given to the standard barcode image of a 12 digit GTIN that is commonly used in North America.

What is the difference between an EAN and a UPC?

A UPC is usually a 12-digit barcode used in North America to identify most products. The rest of the world uses 13-digit EAN barcodes to identify products. However, both types of numbers and barcodes are part of the GS1 System of international standards, so both are accepted globally.

If I already have a UPC do I need to get an EAN?

No. A UPC barcode and 12 digit GTIN does the same job as an EAN barcode and 13 digit GTIN. The UPC originated in the US, but is part of the global GS1 System. So if you licence UPCs from a GS1 organisation, you’ll have no problems using them globally. When a 13 digit number is required you can add a zero to the front of your 12 digit GTIN.

How do product identifiers work?

A product identifier is simply a number that allows you to uniquely identify your product.
The GS1 System of product identification ensures that the number you have given your product is unique. Retailers have been using GS1 product identifiers – GTINs – to manage their inventories for over 40 years.

Today, with 100s of millions of products now listed online on websites and marketplaces this is more vital than ever. Marketplaces use product identifiers to manage their product catalogues, so if your product is mis-numbered and has the same identifier as another product it causes a data conflict.

Do I need a product identifier?

Yes. If you’re trading online on a marketplace such as Amazon, eBay or Google Shopping. They all now require you to input a product identifier when you list your product.

Why do I need a product identifier to sell my product online?

As marketplaces develop their websites, they need more information about what’s listed in their catalogues. As with traditional retail, knowing what’s available to buy in their catalogues is essential to keeping shoppers happy – and buying your products.

Why are product identifiers becoming important for online sellers including eBay and Amazon?

Product identifiers will help you to grow your business. They’re a great way to improve traffic to your listings. This is because search engines such as Google and Bing are also using product identifiers as a way of tying together the information about your product in a structured way – this makes it easier for them to return your listings for relevant search queries.

Uniquely identified products also allow the marketplaces to better understand what’s in their catalogue. Marketplaces such as Amazon and eBay are using product identifiers to structure product data on their websites so that they can improve a shopper’s experience. Product identifiers are used to drive features such as product reviews and to create smarter offers for shoppers.

Do I need either an EAN or a UPC product identifier?

It doesn’t matter. If you’re a GS1 UK member you’ll get a company prefix that enables you to create 13 digit identifiers – GTINs – that are used in EAN barcodes. But 12 digit GTINs and 13 digit GTINs, which are represented by UPC and EAN barcodes, are both part of the global GS1 System so both will be suitable for your products.

I am a fashion retailer. Do I need product identifiers to sell on Amazon, eBay or Google Shopping?

Amazon requires GTINs for the entire fashion category – clothing, footwear and accessories.

Google Shopping requires GTINs for shoes, sunglasses, handbags and watches. And in all categories Google states that “Whenever GTINs are available, we strongly recommend providing them in the ‘GTIN’ attribute.”

For eBay, GTINs are required for all single and multivariate listings for new, relisted, revised and Good ‘Til Cancelled listings of new and manufacturer-refurbished items. There are some exceptions for the clothing, footwear and accessories category.

Will my product identifiers work with Amazon?

Yes, if it’s from a GS1 organisation. Amazon accept GS1 GTINs in all of their forms, so if you have a GTIN-13 (or EAN number) or GTIN-12 (or UPC number), when you’re listing a new product you’ll most likely be asked to provide one. There are some exceptions and exemptions for some products.

Are product identifiers issued by an official body?

GS1 UK LogoGS1 is the not-for-profit organisation that administers and maintains the GS1 System of supply chain standards globally. These standards include product identifiers such as GTINs, as well as EAN and UPC barcode specifications. GS1 work with over 2 million members worldwide to ensure our standards support industries as they develop and grow.

Are GS1 product identifiers permitted for use globally?

GS1 GTINs, EAN and UPC barcodes are used in the UK and all over the world. Over 150 countries use the GS1 System – with over 6 billion GS1 barcodes scanned every day!

Will my product identifiers ever expire?

When you join a GS1 organisation you’re allocated a unique company prefix that allows you to generate your GTINs. This prefix is licensed to you on an annual basis. Similar to your TV license, as long as you need to identify your products you need to renew your license.

Do I have to pay renewal fees?

As your company prefix is licensed from GS1, this means there is an annual license fee for your membership.

Will my product identifiers be unique to me?

All GS1 members are licensed a unique company prefix which enables them to give each of their products a unique GTIN – so as long as you assign the numbers correctly you won’t have any problems.

Will my product identifiers work in a country other than the UK?

Yes. The GS1 System is used in over 150 countries worldwide. There are millions of trading partners all over the globe using our standards for product identification and barcodes.

Is there anything that I need to do after I receive my product identifiers from GS1?

A GS1 membership leaves the best person in charge to manage your product data – you. So they won’t send you each identifier individually. You’ll get a unique company prefix and from this you can assign up to 100,000 GTINs – so you can be sure you’ll never run out

You can manage all your numbers online using their secure online service, My Numberbank. You’ll find this in the member’s area of the GS1 website.

When will I receive my product identifiers – how long does it take?

You can register at and you’ll receive your company prefix in a matter of minutes – which means you can start assigning GTINs immediately.

Online Seller UK can help you with these changes on eBay or Google Shopping. They say that they “have already helped UK eBay sellers to update thousands of listings in matter of days at a very reasonable cost and if you need help on this please get in touch“.

  • 2 years ago

    Can you add a piece on ISBNs please.

  • Dean
    2 years ago

    I’d like to know how and where the other barcode resellers fit in.
    Companies such as

    Do such companies “buy” / “purchase” / “license” barcodes from GS1 and resell them?

    In the past I’ve paid for small runs of barcodes from webistes other than GS1 and I don’t pay an annual license fee.
    What am I letting myself in for?
    Anything? Will my barcodes not be unique? Could they be re-assigned to someone else? Are they just made-up?
    Or have I got away with paying less for my barcodes than I would have if I had got them from GS1?

    I genuinely don’t know and having seen so much confusion about this on an eBay Facebook group I would like to know the differences from an expert.
    If I’ve made a mistake already, I don’t want to make it again.


    • Kyle
      2 years ago

      You used to be allowed to resell your own barcodes but the terms were changed something like 15 years back. However blocks that were bought before the change are still under the old terms and can be resold, hence all the resellers.

      You are meant to wait five years between changing the product a barcode applies to but in our experience even household names don’t obey that rule. So yes in theory it’s possible that the reseller could sell your code to someone else and it won’t be unique anymore.

    • 2 years ago

      Hi Kyle,

      Just to clarify, no GS1 office allowed the reselling of numbers at any point. You might be referring to the CSA that GS1 US entered into in 2003, allowing previously registered companies to carry on using their barcode numbers without paying further membership fees. This has now been amended and the membership structure is standardised across all GS1 membership organisations globally.

      You are right in saying that barcode numbers can be recycled. This can generally be done after four years for normal retail products. Other products, e.g. anything related to healthcare, do not allow reusing barcodes regardless of how much time has lapsed for obvious health and safety reasons.

      Something else worth considering is that for online listings, e.g. with Amazon, the barcode numbers cannot be reused due to the way that the platform works. If you try to use a barcode number that has previously been listed, it will simply be rejected by the system even if the product is no longer on sale. The decision to recycle a barcode number is ultimately at the discretion of the brand owner/ GTIN licensee and depends on how, where and what the organisation is selling.

      Let us know if you need any further clarification with regards to this!


      Leo @ GS1

    • 2 years ago

      Hi Dean,

      The companies you can find online that sell barcode numbers are not associated with GS1 in any way.

      You will find that some of them sell on numbers acquired from US companies registered with GS1 US before 2002, others simply create numbers that do not carry any value and do not exist. In either case, there is no guarantee that the number will work and the information linking to the barcode will never be traced back to your company. This will potentially cause a lot of issues with your customers and sales channels.

      Established retail organisations and sales channels (Tesco for example) also require you to provide a certificate confirming you have a valid GS1 membership without which you will not be able to trade with them.

      Another thing to be mindful of is that there is no guarantee that the numbers you buy through a re-seller have not been previously sold to someone else, meaning that there is a very high risk of duplication amongst these re-sold number. As all GS1 numbers are issued on a license agreement, we can ensure that no duplication occurs and that all the numbers provided are globally unique.

      Hope this clarifies things for you!

      If you would like to learn more or if you need any further support please take a look at our website and by all means get in touch,

      Leo @ GS1

  • Tony
    2 years ago

    Does anybody know if it has an effect on ebay search placement when you select the ‘Does not apply’ option instead of an EAN number for products that do not have any number? Is it worth purchasing EAN numbers for these?

  • Steve
    2 years ago

    What happens when a “licensee” fails to renew their license? If their company prefix is subsequently licensed to another company, how can they be sure that any new GTINs produced are not already in circulation on the old company’s products?

    If a prefix can’t be licensed to a second company (which is the only way to stop this happening) what is the point of anyone continuing to pay an annual license fee?

    • 2 years ago

      Hi Steve,

      When a license is not renewed, a prefix gets returned to our internal database and can be recycled by being allocated to another company.

      For those selling in physical stores, this means that if the previous licensee still has goods in the supply chain, they will encounter multiple issues such as fines from their customer and product recalls because the prefix is no longer licensed by them.

      If you’re selling online (e.g. Amazon etc), the original membership cannot be cancelled unless all the product listings are removed. Any new listing will be validated against the current licensee so again any listings with invalid or old GTINs can be challenged and removed by the current licensee.

      We also carry out regular compliance checks in collaboration with retailers and retail chains to monitor the usage of barcodes and their legitimacy. This helps us keep track of any abnormalities and make sure that there is no product duplication.

      I hope this helps,

  • Hamed
    2 years ago

    We are planning to implement barcode scanning in our warehouse for inventory control of medical supplies, but we have to link the GTIN numbers with our item codes in order for our system to be able to identify the item.
    I need to know how can we get the GTIN numbers of the medical supplies that already they are members in GS1?

    • 2 years ago

      Hi Hamed,

      If you use a GS1-128 barcode on a pallet label it will allow you to encode a variety of information into the barcode itself using application identifiers, e.g. expiry date, batch number.

      We would suggest that you use the barcode numbers that are already available on the packaging of the medical products. If the barcode numbers are not available on the packaging of the products or on any literature that you have for the products, we would suggest that you contact your suppliers or the manufacturer of those products to obtain the barcode numbers. If your suppliers are GS1 members then they should be able to provide you with this information, if they are not yet GS1 members you can ask them to contact us to find our more about membership.

      We’d recommend getting in touch with us to discuss this further as we would need to clarify a few details. You can call us on 02070923501 or drop us a line at and we would be more than happy to help you with this.

      Leo @ GS1

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