Decoding the Lines: Making Sense of Product Identification Codes

The barcode is a ubiquitous part of everyday life. According to GS1 the ‘beep’ of a barcode being scanned at a checkout occurs over 6 billion times every day!  Surprisingly, the barcode was invented way back in 1952 by Morman Woodland and Bernard Silver. Their invention was based on Morse code that was extrapolated to thick and thin bars. However, it took another twenty years for the barcode to find a commercial use. 

The first ever use of a barcode in retail, which occurred in 1974, was when Marsh supermarket in Troy, Ohio used a scanner to scan the UPC barcode on a pack of Wrigley’s chewing gum. It wasn’t long before barcodes became the standard in automated supermarket checkout systems, and the rest, as they say, is history. Today UPC barcodes are pre printed on almost all items other than fresh produce. 

Aside from the obvious benefits of speed and efficiency at checkouts, a barcode system has numerous benefits in terms of sales and inventory tracking, and in supply chain management. Barcodes in inner cartons, outer cartons, on pallets and shipping containers, all provide a critical means of tracking movement of goods up and down the supply chain.  

Much as it would be simple if there was one universal barcode system, the reality is that as supply chains have become more complex the need for different types of identification codes has grown. All of these codes are designed to optimise a globally recognized way to uniquely identify products in the supply chain, ensuring consistency and efficiency across businesses and countries.  

As we are specifically interested in the retail channel, this page explores the different types of codes you are likely to encounter, the similarities and the differences. 

Barcode icon. Scanner barcode illustration symbol. Sign scan sticker vector flat.
So what is a Barcode?

In its simplest from, a barcode is a visual representation of data that can be read by machines. It’s typically composed of parallel lines of varying widths and spacings, though 2D variants like QR codes exist as well. They are used in a wide variety of settings, from retail products to library books, to track inventory, manage sales, and more. The barcode most commonly used in retail settings is the Universal Product Code (UPC).

A UPC is a specific type of barcode used primarily in the United States and Canada to track products in stores. Its main features and details include: 

    • A numeric code that typically has 12 digits. These digits uniquely identify a product and the manufacturer.
    • The UPC code is represented as a series of black bars of varying widths, along with the 12-digit number usually printed at the bottom. These bars can be scanned at the point of sale to quickly and accurately process items. 

Components: The first 6 to 9 digits (depending on the length) are the manufacturer’s unique identification number. The next set of digits represents the product number. The final digit is a checksum, used to verify that the number has been read correctly when scanned. 

There are a number of different types of UPC: 

  • UPC-A: This is the standard 12-digit UPC and is the most commonly used format. 
  • UPC-E: A shorter, 6-digit version of the UPC code. It’s a compressed version of the UPC-A code, used for products with limited label space. 

Usage: UPC codes are used for various purposes including tracking inventory, managing sales, and streamlining the checkout process. Manufacturers obtain their UPC codes from the GS1 organization, which ensures that each code is unique. 

Global Equivalents:  While the UPC is primarily used in North America, the EAN (European Article Number) serves a similar purpose internationally. The two are related; for example, a 12-digit UPC can be converted to a 13-digit EAN by adding a leading zero.

An EAN is a standardized barcoding system used internationally for identifying products. It’s a type of Global Trade Item Number (GTIN) and is managed by the GS1 organization. Here’s a breakdown of the EAN: 

The most common forms of the EAN are: 

  • EAN-13: This is a 13-digit barcode and is the standard version of the EAN. It is used worldwide. 
  • EAN-8: A shortened 8-digit version, often used on smaller products where a full EAN-13 might not fit. 

An EAN typically consists of: 

  • GS1 Prefix: This indicates the country in which the manufacturer’s identification code was assigned. Note that it doesn’t necessarily indicate the product’s country of origin. 
  • Company Number: Assigned by the GS1 organization to member companies. 
  • Item Reference: Assigned by the company to each specific product. 
  • Checksum Digit: A calculated number used for error checking when the barcode is scanned. 

Usage: EAN barcodes are used primarily in retail and wholesale. They are scanned at points of sale, and they help in tracking inventory, order management, and other logistics. While EAN originated in Europe, it’s now used globally. 

Relation to UPC: The UPC (Universal Product Code) is the North American equivalent of the EAN. An EAN-13 code with a leading ‘0’ is equivalent to a 12-digit UPC code. 

Barcode Appearance: The EAN is represented as a series of black bars of varying widths, along with the 13-digit (or 8-digit for EAN-8) number usually printed at the bottom. These bars can be scanned electronically to quickly identify the product. 

Assignment: Companies that wish to use the EAN system for their products need to join the GS1 organization to get a unique company prefix, ensuring that the EANs they assign to their products are unique across the world. 


A GTIN is a unique and internationally recognized identifier for trade items, such as products and services, that are sold, delivered, invoiced, or otherwise handled in the supply chain. UPCs and EANs are examples of GTINs. 

Here are some key points about GTIN: 

  • The GTIN system is managed by GS1, an international non-profit organization that develops and maintains global standards for business communication. 
  • A GTIN can be of varying lengths depending on the type of product and where it’s sold: 
  • GTIN-8: An 8-digit number mainly used for smaller packages. 
  • GTIN-12: A 12-digit number, also known as the Universal Product Code (UPC), primarily used in North America. 
  • GTIN-13: A 13-digit number, also known as the European Article Number (EAN-13), primarily used outside of North America. 
  • GTIN-14: A 14-digit number used to identify trade items at various packaging levels. 

Usage: GTINs are used in retail, wholesale, and e-commerce settings across various sectors. They’re encoded into barcodes that can be scanned at points of sale or during logistics operations.  

Uniqueness: Every product variant (such as different sizes or colors) has its own GTIN, ensuring clear distinction between items. 

Global Recognition: Given its international standardization, a GTIN ensures a product is uniquely identified worldwide. 

Supply Chain Efficiency: GTINs facilitate efficient trade and supply chain operations by streamlining the tracking, ordering, and inventory management of products. 

Relation to Barcodes: GTINs are often embedded in barcodes, allowing for electronic scanning and processing. The most common barcodes that carry GTINs are UPC (for GTIN-12) and EAN (for GTIN-13). 

Assignment: Companies that wish to assign GTINs to their products must first obtain a unique company prefix from GS1. This prefix ensures that the GTINs a company assigns to its products are unique worldwide. 

Amazon likes to be different, so they have established their own unique product coding system. An ASIN is a 10-character unique identifier assigned by Amazon to products within its marketplace. 

Each product sold on Amazon has a unique ASIN. For books, the ASIN corresponds to the book’s ISBN, but for all other products, a new ASIN is created when the item is uploaded to the platform. 

ASINs are used to manage the vast product catalogue on Amazon and ensure each product is unique. 

Manufacturers and retailers will sometimes generate and use SKU numbers in addition to UPCs. These codes are completely unique from one business to another, and therefore different to the barcodes / UPCs discussed above.  

Typically a SKU number is between eight and twelve characters and contains pertinent information about a product’s type, style, brand, colour, size etc. For example in the apparel world, which is SKU intensive due to style/colour/size combinations, the first two digits of the SKU number might indicate the category, the next two the style, the next two the colour and the final two the size. However, because the SKU nomenclature is created and maintained by the retailer or the manufacturer, there are no universal rules for what each digit represents. 

Some retailers will create their own unique product identifier based on their needs and nomenclature, which is supplementary to the barcode or UPC. They will also give this code its own name, such as a ‘Keycode’ (BigW) or a ‘Fineline number’ (Walmart). These supplementary codes may be used to track variants in the system. For example, a change of packaging or a temporary promotion. In these examples the code will be assigned to the variant in order to be able to analyse sales, even though the product is the same product. In other instances, a manufacturer may make a product with a variety of different designs (eg a baby bottle with different cartoon characters) where the barcode or UPC is the same, so assigning a different keycode can help analyse the popularity of the different designs. 

The Need and the Expertise

In an ideal world, we’d have a single, globally unified system for product identification, simplifying tracking and management for both retailers and manufacturers. However, the landscape of product codes is as diverse as the world’s cultures. From region to region, and even within them, various identification systems have evolved, each catering to specific needs in supply chain management, inventory tracking, and performance analysis.

This diversity underscores the importance of harmonizing data. It’s crucial to ensure that products can be seamlessly tracked across different coding systems. Enter Krunchbox. With a expertise spanning fifteen years, we’ve been at the forefront of consolidating and harmonizing retail data. Our expertise encompasses data from over two hundred global retailers, placing us in a unique position of unparalleled domain knowledge.

Facing challenges navigating the maze of product codes?   Get in touch and let Krunchbox guide you.