Barcode basics - How to obtain UPCs & GTINs for your products

What is a UPC?

The UPC or Universal Product Code is the barcode found on all products. It is the strip of thick and thin lines that can be scanned to find information on the product. The most common use of them are when they are scanned in Brick & Mortar stores at the till.

What is a GTIN?

The GTIN or the Global Trade Item Number is the string of numbers found underneath the barcode/UPC. It is a numeric version of the UPC. 

In the UK and Europe, GTINs are usually 13 digits long. The entire barcode is called an EAN (European Article Number).

In the US it is only 12 digits long. You might see shorter 8 digit numbers, used on small products. 14 digit GTINs may be used to identify cases of products.

Books have their own unique version of a barcode named the ISBN (International Standard Book Number) – it is the only barcode that remains the same as the ASIN (Amazon Standard Identification Number) when selling on Amazon.

Simply put, to sell your products you need a barcode and for that barcode you will need a unique GTIN. This will differentiate it from all other products.

Barcode UPC GTIN example

Where should I obtain my barcodes?

There are a plethora of companies that sell UPCs and GTINs but it is best to find a trusted source. We recommend obtaining your product identifier directly from Global Standard One or GS1 to ensure that your product codes are unique.

Amazon verifies the authenticity of product identifiers by checking the GS1 database. UPCs that do not match the information provided by GS1 will be considered invalid and might be removed from the site.

How do I start?

To start assigning barcodes to your products, you’ll need a GS1 Company Prefix. Your Company Prefix is your unique code of numbers found on your GTIN for all your products. It is the 1st 6 to 9 digits. Your company prefix will remain the same on all your produced barcodes but the rest of the numbers will differentiate for each of your products.

The GS1 will take into account the number of products your company may plan on selling when you apply for your company prefix. This will affect the length of your company prefix as a short prefix will allow for more GTIN variations.

With a company prefix in place, the rest of the number order is up to you. You get to decide what digits you place as no other product will have the same GTIN. Your unique company prefix prevents this. The company prefix plus your unique code will ultimately make up 11 digits of the UPC/GTIN. The 12th and final digit will be calculated by GS1. This last number is called the check digit or checksum. It verifies that the information placed has been entered correctly.

Remember that every product you create a barcode for must have a different code or ID. This includes variations of the same products eg. a notebook with a red cover will have a separate barcode than the same notebook with a green cover. 

You can also apply more than one UPC/GTIN to a product. If you want to sell a product in a different category or even to determine where your product is manufactured, it is possible to apply for a different barcode. 

Multiple UPCs can be applied to a single Amazon Standard Identification Numbers (ASIN) but only one ASIN can be applied to a product. If Amazon finds a product with a different ASIN than same products, it may be removed.

It is most cost effective to include barcodes during the original design of your product as it can be directly printed and incorporated onto the product or packaging via a digital barcode file sent by GS1. Only .eps formatted files should be used for a digital barcode print.

However, not all products are suitable for incorporating the barcode onto the product such as certain handmade items and you may have already packaged your products before applying for a UPC. In this case, a printed barcode label must be placed on each item.

Make sure that the barcode is clearly visible and accurate in either case as products without one will not be valid to sell and you could inflict chargebacks from Amazon or have your products removed from the store.