This page takes new bar code users through the basic steps they must take to begin using bar codes.

• Step 1: Get a GS1 UK Company Prefix
• Step 2: Assign numbers
• Step 3: Select a bar code printing method
• Step 4: Select a primary scanning environment
• Step 5: Select a bar code
• Step 6: Pick a bar code size
• Step 7: Format the bar code text
• Step 8: Pick a bar code colour
• Step 9: Pick the bar code placement
• Step 10: Build a bar code quality Plan

Step 1: Get a GS1 UK Company Prefix

Before a company can begin using bar codes, they must create the numbers that are represented by the bar code. For items that are sold at retail point-of-sale (POS) these numbers are called Global Trade Item Numbers (GTINs).

The first step in creating a GTIN is to obtain a GS1 Company Prefix. GS1 Company Prefixes are licensed to over one million companies today and form the foundation of uniquely identifying everything in the supply chain. To obtain a GS1 Company Prefix you need to join GS1 UK.

To obtain a GS1 Company Prefix you need to join GS1 UK. You can do this on-line from the link join GS1 UK or we can take you through the application over the phone, if you pay by debit or credit card. We do not accept American express or Diners Club.

Once you have joined, we will assign you with your own series of numbers, which are unique to you and your products. You will receive an email with instructions so you can access your numbers immediately.

Using the GS1 standards, you can create GS1 standard bar codes that are valid worldwide, so you will be able to sell your products into any organisation anywhere in the world.

If you need any further assistance setting up your account please contact one of the Service Team on freefone 0808 178 8799.

For costs on joining please see our Membership section for Types and fees.

If you need to trade in the US or Canada, please speak to the Service Team before you decide to join.

Step 2: Assign numbers

After receiving a GS1 Company Prefix, a company is ready to begin assigning GTINs to identify their trade items (products or services), GLNs (Global Location Numbers) to identify themselves (as a legal entity) and other locations, and SSCCs (Serial Shipping Container Codes) to logistic units.  Individual company assets, returnable assets (returnable pallets, kegs, tubs etc) and service relationships can also be identified with other GS1 Identification Keys.

Step 3: Select a bar code printing company

To begin, you should decide what you are bar coding and if the bar code will carry static or dynamic information.  An example of static information would be simply a product identification number (GTIN) on a product. An example of dynamic information would be printing serial numbers on product labels.

If your bar code has static information and you need a small or large volume of labels then you could ask a printing company to print your labels. If you need to print labels with dynamic information you will probably need an on-demand printer such as a thermal transfer printer in your warehouse.

Knowing how you will print your bar code is an important question to answer in developing a good bar code implementation plan. Please consider using a GS1 UK Solution Provider to assist you in making the right selection or to print the bar codes for you.

Step 4: Select a primary scanning environment

The specifications for bar code type, size, placement, and quality all depend on where the bar code will be scanned.

There are four basic scanner environment scenarios for trade items:

1. Product scanned at the retail POS
2. Product scanned in general distribution
3. Product scanned at retail POS but also scanned in distribution
4. Special environments like medical device marking

By knowing where your bar code will be scanned you can establish the right specifications for its production. For example, if a product is scanned at retail POS and in general distribution, you will need to use an EAN/UPC symbol at a size of at least 150% so that it can be scanned by distribution scanners as well, and ensure its position meets automated distribution scanning requirements.

You can find more information about this in Bar coding - getting it right or in the GS1 General Specifications.

Step 5: Select a bar code

Selecting the right bar code is critical to the success of your bar code implementation plan, but here are some high level tips:

• If you bar code a trade item that will be scanned at the retail POS, you must use an EAN/UPC symbol (although GS1 DataBar can now be considered in some special cases)
• If you are printing a bar code with variable information like serial numbers, expiry dates, or measures, then you will use GS1-128, GS1 DataBar or GS1 DataMatrix symbols
• If you just want to print a bar code carrying GTIN on a corrugated carton, ITF-14 may be the choice for you

There are of course many other factors to consider so please read Bar coding - getting it right for more information.

Step 6: Pick a bar code size

After the correct bar code symbol is specified together with the information to encode in it, the design stage begins. The size of the symbol within the design will depend on the symbol specified, where the symbol will be used, and how the symbol will be printed.

EAN/UPC symbols differ from ITF-14 and GS1-128 symbols because they are scanned by retail omni-directional scanners. This means that EAN/UPC symbols have a fixed relationship between symbol height and width. This proportion remains the same whenever the bar code is enlarged or reduced in size.

EAN/UPC symbols have a nominal or 100% height and width, and a range of allowable sizes from 80% to 200% of the nominal size.  This range of sizes is often referred to as the magnification range. The minimum, nominal and maximum magnification for EAN/UPC symbols are shown below.

Minimum (80%)

Nominal (100%)

Maximum (200%)

In order to reduce the amount of space EAN/UPC symbols take up on a design a decreased symbol height might be specified. This process, called truncation, should be avoided. This is because of the negative impact it has on scan rates for retail omni-directional scanners.

When EAN/UPC symbols are used in logistics (shipping and distribution) as well as at the retail POS, the range of magnification allowed is limited to between 150% and 200%. An example of this would be the symbol on a carton used for a large appliance (e.g. a television or microwave oven).

ITF-14 and GS1-128 symbols also have a range of sizes. ITF-14 and GS1-128 symbol sizes are often specified by the width of the X-dimension instead of magnification values. You can find information on the sizes for ITF-14 and GS1-128 symbols based on the application where they are used in Bar coding - getting it right.

Consideration of the printing process

The final major consideration for symbol size is the capability of the selected printing process. The minimum size (magnification) and correct Bar Width Reduction (BWR) for a symbol vary by printing process and even from press to press. Printing companies should establish a minimum symbol size (magnification) and BWR to achieve acceptable and repeatable quality results.

Step 7: Format the bar code text

The text beneath a bar code is important because if the bar code is damaged after printing, then the text is used as a back-up. The OCR-B font was originally specified for use with EAN/UPC symbols, but GS1 now permits any font as long as it is clearly legible. The numbers should normally be approximately 3 mm tall.

The human-readable text for ITF-14 and GS1-128 symbols must be clearly legible and in a size proportional to the symbol size.

All GS1 Application Identifiers must be enclosed in parentheses in the human readable interpretation, but the parentheses are not encoded in the symbol.

Step 8: Pick a bar code colour

The optimum colour combination for a bar code is black bars on a white background. If you want to use other colours, the following may help you in choosing satisfactory ones:

• GS1 bar code symbols require dark colours for bars (e.g. black, dark blue, dark brown or dark green)
• The bars should always consist of a single colour and should never be printed using a multi-colour print process
• GS1 Bar Code Symbols require light backgrounds (e.g. white, red, orange or yellow)

Again, by staying with black bars and white spaces, you have selected the optimal combination, but other colour combinations can be used. Bar coding - getting it right contains further information on this.

Step 9: Pick the bar code position

The bar code should normally be positioned on the natural reverse of a product, towards the bottom right-hand side. It should be kept at least 8mm away from seams, folds and edges of the item to minimise the likelihood of damage.              

Step 10: Build a bar code quality plan

All bar codes can be checked for quality using an ISO/IEC 15426-1 compliant verifier and most companies will ensure that their packaging suppliers use one to assess the scannability of the printed bar codes. If you are printing bar-codes on demand you might need to consider using a verifier to guarantee the quality of your symbols. More information about using verifiers can be found here.