GTIN Allocation

Who should allocate Identification Numbers?

Generally, the organisation that owns the specifications for a product (or the Brand Owner) is responsible for the allocation of the GTIN, regardless of where and by whom, the product is manufactured. In some instances, such as in the manufacture of own brand products or where manufacturing is outsourced, the following may also be responsible for allocating GTINs:

  • An importer or wholesaler: if the importer or wholesaler has the product manufactured in any country under a brand name that belongs to the importer or wholesaler, then they are responsible for allocating the GTIN.
  • A retailer: if a retailer has a product manufactured in any country and sells it under a brand name that belongs to that retailer, then they are responsible for allocating the GTIN.

Some companies produce the same product in different countries or at several manufacturing facilities. In this case the number should be allocated and managed centrally or by just one of the companies or plants.

Building a GTIN 13

In the following example we will allocate an EAN 13 for a fixed weight consumer unit intended to be scanned at the retail point of sale.

The GS1 Company Prefix is the starting point for generating a GTIN 13. In Ireland, the prefix may be 7, 9, or 11 digits long, e.g. 539123456 depending upon the capacity required by the allocating company. The first three digits, 539, indicate that the number was issued by GS1 Ireland and the remaining digits e.g. 123456 uniquely identify the allocating organisation. The full prefix digits should be used comprehensively and as a whole.

Please Note:539123456 is used for illustrative purposes only. Please refer to your membership documentation from GS1 Ireland for the correct number which has been allocated to your company.

After the Company Prefix you must add an item reference number for the product or service you wish to identify. As the GTIN will be 13 digits in total (12 plus a check digit) the length of the item reference number will vary depending upon the length of your company prefix number.

The item reference number will be:

5 digits long if you have a 7 digit prefix

3 digits long if you have a 9 digit prefix

1 digit only if you have an 11 digit prefix

The length of the item reference number indicates the size of the number bank available. A five-digit item reference number indicates a bank of 100,000 numbers from 00000 to 99999. Similarly a three-digit item reference means that your company has the use of 1000 unique numbers from 000 to 999. An 11 digit prefix indicates a bank of 10 numbers has been allocated to you.

Example: a 9 digit prefix and a 3 digit item reference number:
539 123456 789 where 789 is the trade item reference number.

It is best practice to allocate numbers to your products or services in a sequential manner starting from 0 and working your way up. The numbers allocated should be non-significant and it is not recommended that various parts of the number bank are reserved for use for different categories of product.

The next and final step in completing your full GTIN, is the calculation of the Check Digit.

Building a GTIN 14

To generate a GTIN 14 or outer case code simply allocate a new 12 digit number from your number bank as outlined in the section above.

If the case you wish to identify contains fixed weight consumer units, prefix your new 12 digit number with 0 and then calculate the check digit in the standard way.

If however, the case contains variable weight consumer units, prefix the 12 digit number with a 9 and then calculate the check digit.

This fourteen digit number may now be printed as either an ITF 14 or GS1 128 bar code symbol.