Basic introduction to retail barcodes



    Please click the [ Mark Complete ] button at the bottom of this page when you’ve achieved the following goals:

  • Understand the concept underpinning the barcoding system, and be familiar with common retail barcode formats
  • Be able to clarify for a customer how the barcode bars are simply a graphic representation of the number, and further action needs to be taken to associate products with these numbers.
  • Understand the allocation of a single barcode to a single product or variant of that product.
  • Explain how a customer can incorporate a barcode on their product packaging if they’ve already printed the packaging prior to purchasing a barcode.
  • Be able to explain to customers how they can either buy barcodes outright through a barcode reseller such as IBN, or arrange barcodes at greater expense through licensing bodies such as GS1.
  • Understand how barcode registration is not compulsory, but how IBN offers it anyway as a free service.



The barcoding system was created in the 1970s by George Laurer. It is a universal system for keeping track of items and prices in inventory systems worldwide.

This is now used by almost all retailers, and works under the premise that each product is assigned a unqiue number which has never been used on any other product worldwide. This unique number is encoded in the barcode image (black bars).


Retail Barcode types:

Barcode subsets of EAN-13    Barcode subsets of EAN-13

The majority of retail barcodes are either 13 digit EAN-13 barcodes, or 12 digit UPC barcodes which are a subset of EAN numbers. The only exceptions are books (which use 13 digit ISBN barcodes), magazines (which use 13 digit ISSN barcodes) and very small products which use 8 digit EAN-8 barcodes. You will learn more about the difference between EAN-13 and UPC barcodes in the next lesson, but in general they perform the same function.


How do barcodes work?

There is NO product information encoded in retail barcodes, ONLY a number. Retail Barcodes are simply unique numbers, drawn from a large international database and allocated to a customer.
The bars of the barcode ONLY encode the number shown under the bars; they signify no other data.
When a barcode is scanned, the scanner ONLY identifies the number.
So how does the checkout till know what product it is and what price to calculate?

Each retailer has to manually associate the barcode number to their product details within their internal database:

Given that the barcode is simply a number, when a retailer first receives a product, they need to scan (or type) the barcode number into their computer system, and then digitally associate it with a product.

They will also enter other product information such as product name, description, retail price, supplier etc.

Thereafter, when the barcode is scanned at the checkout, the correct information will be displayed. Larger retailer chains will require you to enter all this information onto a form, which is then entered into their computer system automatically.


A different barcode number is needed for each unique product or product variant:

For example:

  • For 3 different products you need 3 barcodes.
  • For 3 different products where each has 2 size variants, you will need 3 x 2 variants = 6 barcodes.
  • For 3 different products where each has 2 size variants and 5 colour variants, you will need 3 x 2 variants x 5 variants = 30 barcodes.

You can then sell unlimited numbers of a unique product with a particular barcode on it.


Using Barcodes:

We supply barcodes as digital images, which then need to be integrated into the product packaging. The best way to get a barcode onto a product is to incorporate the barcode image in the design of the product packaging before it is produced and printed.

However, if customers have already printed their product packaging, they can then add a barcode using a separate sticky label.


Retail barcode numbers are globally unique numbers and are protected: 

Nobody can legitimately make up barcode numbers to use in the public or business domain. All legal retail barcodes (including ours) originate from the GS1 system.

If you are ONLY selling your products within your own store, with no reference to the outside world, then you can make up any barcode system you wish.

Legitimate barcode numbers need to be either

  • Purchased outright for life (from us at IBN for example), or
  • Obtained by means of a license arrangement from a legitimate licensing organisation. This is usually very expensive and the trade is globally monopolised by a single body, GS1. GS1 is our primary competitor

GS1 maintains a global database of all legitimate numbers at

If a number is not listed in this database, it has been made up.

NOTE: Fake barcode dealers often copy legitimate numbers, so if you check a number on and it shows up there, it is not necessarily being legitimately used – it may have been copied. These are not legal requirements, but barcodes do need to meet accepted retail industry standards which means originating from the GS1 system.


Retail barcodes do not have to be registered, but we offer registration for free:

Registration is not compulsory, but we provide it as a free service. If you purchases retail barcodes (EAN or UPC) from our IBN you will be able to register your barcode numbers and product details for free on the International Barcodes Database. Registration will be covered in more detail in later lessons.