Keywords: re-use re-using GTIN barcode allocating
GS1 has issued a Decision Support Tool to help you decide if a new GTIN is required.
Broadly the principles are that the brand owner is responsible for allocating GTINs and each variant of a product must be identified with its own unique GTIN.
The complete Rules may be found at http://www.gs1.org/1/gtinrules/
The Bar coding basic user guide V3 discusses re-using item numbers:
Best practice is to never re-use numbers so that accidental duplication is impossible. For this reason numbers on medical and pharmaceutical products must never be re-used.
The GTIN for any other product may be re-used if it is at least four years since the number was last used to identify something else. Even if the first product had a very short shelf life the number should not be re-used before this time has elapsed or it may cause confusion with your trading partners.
The only exception is for clothing, when numbers can be re-used after 30 months. This is because many of these are used to identify fashion items that are normally sold for only one season.
It is always worth checking whether re-using numbers will cause any problems with your major customers. In the music industry, for example, re-using numbers may cause problems because a re-issued recording may require the same number it had 10, 20 or 30 years ago