GS1 Barcode Technology and Standards

Barcoding has been in use since 1974 when the first barcode was scanned in a retail environment in Ohio USA. Since then, the use of this technology has expanded into the warehouse and more generally throughout the supply chain including mail and parcel delivery.

Barcoder 250 is a stock control and warehouse management system that makes extensive use of barcodes to deliver the benefits of barcode technology. Examples of these benefits include:

·         Very easy and accurate capture of information

·         Worldwide unique identification of products and assets

·         Visibility of product movements throughout the business process.

·         Extensive management reporting becomes possible

·         Improved financial efficiency due to reduced stock holdings

·         Increased competitive advantage through improved delivery times and responsiveness.

·         Working with a global standard that is understood World-wide.

While it is not always necessary to use an international standard for the barcode format, Barcoder 250 is fully compatible with the GS1-128 barcode and it can be used by the system any time the customers’ business process demands it.

The format of the GS1-128 barcode is the subject of a standard created by GS1 the international standards authority for barcodes. GS1 is an international, not for profit, organisation that exists in approximately 110 countries throughout the world.  The UK member organisation is GS1-UK ( and they control the issuing of globally unique barcodes for use by UK organisations.

When implementing a warehouse management system based on barcodes, there are two aspects of the barcode that need to be considered. The first is the actual barcode font that is used and the second is the data contained within the barcode and how it is decoded by the system.

The barcode font used by the GS1-128 barcode is C128. This barcode is available as a built in font in most barcode label printers and can be read by most scanners. It is a one-dimensional font of vertical bars which encodes both letters and numbers. This capability makes it very useful for encoding complex information. The barcode comprises vertical bars of varying width. The barcode scanner reads the widths of blocks of bars and converts these into text that can be read by a computer and also by humans. The most important issue regarding printing barcodes is that they can easily be read by the scanner. It is quite possible to print barcodes that look perfect to the eye but are unreadable by the scanner.

Generally the C128 barcode is not used in retail environments, but can be found extensively in the warehouse and logistical operations such as the transportation of mail around the world. (The standards for mail transportation are controlled by the United Nations agency the Universal Postal Union – UPU (

The power of the GS1-128 barcode format is that it can contain several items of data such as the product code, serial number expiry data and product weight to name just a few. How these items of data are arranged in the barcode is controlled by the GS1 specification.

In the wholesale meat and medical devices markets, GS1-128 barcodes are used extensively by manufactures to provide product traceability and to allow the management of expiry dates. Barcoder 250 is designed to capture this information even if each manufacturer uses different versions of the standard.

An example of a typical GS1-128 barcode is shown below.

It is convenient but not required, to provide human-readable text containing the details of the data incorporated into the barcode. With a suitable system, this barcode can be easily, rapidly, and accurately decoded and read into the warehouse management and stock control system.

As can be seen from the example above, the barcode is separated into a number are sections divided by numbers contained in brackets. (The brackets are not included in the barcode but are added to the human-readable text as an aid to interpretation). The numbers in brackets are called Application Identifiers (AI) and are defined in the GS1 General Specification Section 3. The AI defines the meaning of the data in the following section of the barcode, so the AI’s in the example means:

(01)   Product Barcode as a Global Trade Item Number( GTIN of 14 characters)

(10)   Batch Number or Lot Number
(3102)   Net weight to 2 decimal places
(15)   Best before date

With Barcode 250 these four items of data can be captured in a single scan while receiving the goods into the warehouse so providing full traceability for the item.

There are very many AI’s and their definition may be obtained from the local GS1 authority.

Using the GS1 standard, therefore, means that all organizations in the supply chain can interpret the barcode and use the data contained within it as they require in an extremely efficient and cost-effective manner.