How do I create a barcode number if I'm not using Barcode Manager?

Before you get started

There are two important things you need before you can start creating new barcode numbers. 

The first is to know which barcode licence you have and your prefix length. There are three barcode licences available to GS1 Ireland members - GCP 11, GCP 9, and GCP 7. Which licence you have will determine how many numbers you can create.

• GCP 11 - this licence has an 11-digit prefix and allows you to create up to 10 numbers.
• GCP 9 - this licence has a 9-digit prefix and allows you to create up to 1000 numbers.
• GCP 7 - this licence has a 7-digit prefix and allows you to create up to 100,000 numbers.

The second thing you need before you create new numbers is your complete barcode records of any numbers that have already been assigned, including any obsolete or retired products. This is important as barcode numbers can never be reused or duplicated.

GTIN structure

To create a barcode number, its important to understand the structure of the number.

A GTIN is made up of 3 parts - your company prefix, an item number, and a check digit. 

• Company Prefix - which barcode licence you have, will determine the length of your prefix. Your prefix length and numbers will never change as this identifies your company. If you change the prefix in any way you will be using someone else's numbers.
• Item Number - your prefix length, will determine how many digits your item number is.
  • 11-digit prefix - single digit item number ranging from 0-9
  • 9-digit prefix - 3-digit item number ranging from 000-999
  • 7-digit prefix - 5-digit item number ranging from 00000-99999
• Check Digit - the check digit is the final number of the barcode that is created using an algorithm that needs the prefix and item numbers to find the correct check digit. You will need a Check Digit Calculator to get this number.

Combining these three parts will create a 13-digit number used for consumer units that can be scanned at a till. For logistics units that require a 14-digit number, you will use the same 3 parts and add a leading 0 to the front of the number.

Calculating a GTIN-13

Company A needs to allocate a new barcode to a product. To do this, they will continue in sequence from GTIN 5391234560459 and assign the next available GTIN based on the item number using the following steps:

• Company A will keep their prefix 539123456 as is and make no changes to the assigned prefix.
• Then they will take their last item reference number, 045, and go up by 1 to get the new item reference number 046.

• Next they will add the item reference number to the end of their company prefix which will give them the 12-digit number 539123456046. This is the number they will put into the Check Digit Calculator.
• On the Check Digit Calculator, Company A will type 539123456046 into the spot for the GTIN 13 and click Calculate to get the check digit. The final number will be 5391234560466.
  
• Company A will now save the new GTIN and associated product information in their database to ensure there is a record of all GTINs allocated.

Calculating a GTIN-14

Next, Company A needs to calculate an outer case barcode for shipping their new product. To calculate a GTIN-14 for their case, they will follow the same steps outlined above and put 0 in front of the full GTIN so the barcode number for their case would be 05391234560473.