In assigning the identification numbers, some principles and rules should be noted.

• Who is responsible for numbering trade items?
  Basically only brand owner is responsible to assign the identification number to the trade items. She is not necessary to be the product manufacturers for the products.
• Who owns the numbers after company changes?
  Company status changes as a result of merger/acquisition, partial purchase and split/de-merger will affect the ownership of the GS1 Company Prefix. The being-acquired or being-merged company is no longer to maintain the Prefix and the Prefix should be handed over to the local GS1 member organization. However, treated as exceptional cases, the Prefix can be kept through a mutual agreement between the involved companies and formal notification to the local GS1 member organization.
• When to change the number?
  In theory, it requires a new GTIN when there is a major change to the trade item e.g. greater than 20% change in gross weight. Click HERE to view scenarios of changes.
• When to re-use the number?
  In principle, GTIN for items not being used for 48 months can be re-used. However, it is more or less subject to the product nature.