What are UPCs, EANs, ISBNs (GTINs) and ASINs?

What is a GTIN? 

A Global Trade Item Number (GTIN) is a unique identifier for trade items, developed by GS1 - “GS1 defines trade items as products or services that are priced, ordered or invoiced at any point in the supply chain”. Such identifiers usually come in the form of a 12 digit Universal Product Code (UPC), 13 digit European Article Number (EAN) or 13 digit International Standard Book Number (ISBN). Your product GTIN is represented by the product’s barcode and associated barcode number.

Supplying GTINs for your products is crucial to your business's success both on and off marketplaces as this is how your products are most identifiable by each channel (Google, Amazon, eBay). eBay is increasingly requiring its sellers to provide GTINs on their listings in order to continue improving the buyer experience on-site. Without a GTIN/product identifier on Amazon, you will not be able to list your products at all unless you successfully apply for a GTIN exemption. Google will only show your products if you have provided a GTIN (among other criteria). Amazon and eBay will also submit your products to Google shopping, if eligible.


3 common methods for identifying your product GTIN:

  1. Check the product’s barcode
  2. Request the GTIN from your supplier
  3. Use a barcode lookup website to search for the product


*BE CAREFUL* Avoid purchasing “recycled” codes that are re-sold by online suppliers. Recycled codes can cause complications for your business down the line and often do not justify the upfront savings.

Purchasing GTINs with GS1

It is important to always purchase your GTINs from a reputable source, we recommend purchasing directly from GS1. To get barcodes for your business you’ll first need to join GS1. By becoming a member you obtain the licence for a unique range of barcode numbers. You also gain access to support, training and more.


Adding GTINs to your product catalogue

When adding your GTINs to your product catalogue, it is important that you upload your codes to your ecommerce platform using your existing product update processes - NOT in Codisto. This ensures your ecommerce website continues to be the ‘source of truth’ of your product data and allows Codisto to automatically import and map your data to the corresponding field for each channel. 


Depending on the attribute or meta-field that you add your GTINs to, you may need to use the attribute mapping tool in Codisto to map your GTINs to the correct field. For example, Shopify uses a “barcode” meta-field for providing your GTIN. In Codisto, however, the corresponding field will be dependent on the type of GTIN you are providing (UPC, EAN, ISBN) and must be mapped to the appropriate field so that Codisto knows what data it is sending to each marketplace. See attribute mapping for more information.


Consult your ecommerce platform’s help guides for more information on editing your products.


Universal Product Code (UPC) is (generally) a 12-digit bar code used extensively for retail packaging in United States. (They are sometimes represented as 13 digit codes by adding a leading 0 to make them compatible with EAN’s - see below)

UPC Code
The European Article Number (EAN) is a barcode standard either 8 or 13 digits - never 12.  Each EAN uniquely identifies the product, manufacturer, and its attributes; typically, the EAN is printed on a product label or packaging as a bar code. We require EAN codes to improve quality of search results and the quality of the catalog as a whole. You can obtain EANs from the manufacturer. If your products do not have manufacturer EANs, and you need to buy EAN codes, you; should go directly to GS1 UK http://www.gs1uk.org

For example, the EAN of  "Colgate Total 75 ml" is 4011200296908
EAN code

The International Standard Book Number (ISBN) is a unique commercial book identifier barcode. Each ISBN code identifies uniquely a book. ISBN’s are either 10 digits long or 13 digits long and start with 978 or 979 (i.e. you can convert a 10 digit ISBN to an 13 digit one by adding 978 to the front). All ISBN assigned after 1 Jan 2007 have 13 digits. Typically, the ISBN is printed on the back cover of the book.
For example, the ISBN code for J.K.Rowling's "Harry Potter and the Deathly Hallows", Adult Edition, Paperback, UK edition is 978-0747595823, and this code identifies uniquely this book and edition.

ISBN # with EAN Code

Amazon Standard Identification Numbers (ASINs) are unique blocks of 10 letters and/or numbers that identify items. You can find the ASIN on the item's product information page at Amazon.com. For books, the ASIN is the same as the ISBN number, but for all other products a new ASIN is created when the item is uploaded to our catalogue. You will find an item's ASIN on the product detail page alongside further details relating to the item, which may include information such as size, number of pages (if it's a book) or number of discs (if it's a CD).

ASINs can be used to search for items in our catalogue. If you know the ASIN or ISBN of the item you are looking for, simply type it into the search box (which can be found near the top of most pages), hit the "Go" button and, if the item is listed in our catalogue, it will appear in your search results.

For example, the ASIN for Hasbro's "Monopoly Australia" game is ‎B0768KVCS6.
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