A Global Trade Item Number (GTIN) is a unique number that identifies any pre-defined trade item (a product or service) that may be priced, ordered or invoiced at any point in any supply chain.
Trade items include all services and products, from raw materials through to end user products.
The Brand Owner, the organisation that owns the specifications of the trade item, regardless of where and by whom it is manufactured, is normally responsible for the allocation of the Global Trade Item Number (GTIN).
Different GTINs must be allocated to every different product that the Brand Owner is responsible for, and detailed rules have been developed to help companies allocate them correctly. For further information, please see GTIN Management Rules.
See https://www.gs1.org/standards/id-keys/gtin for more information.