Once an item has been published, the only way to change the GTIN is to un-publish the item and create a new item with the new GTIN.
Note that if you are just changing one GTIN in a product hierarchy the process will become more complex as you will need to first follow the steps below, then 'Un-release' the old hierarchy, remove the old components and then link together the new hierarchy. If you have any questions or complications please contact our Help Desk.
Step 1: Create the new unit by 'Cloning' the old unit GTIN and leave it in "Draft Mode". Depending on how many levels of the hierarchy there are you may need to do this multiple times - and subsequently link together the Supplier Assigned ID. You will also need to ensure that any mandatory fields are now filled out correctly. If applicable, add prices and leave in a "Working" state.
Step 2: End-date and 'Release' the price against your old GTIN (if required by your retailer).
Step 3: Enter an 'End Availability Date' against your old GTIN and 'Release' the changes.
Step 4: Wait for a few minutes, then select the highest level of the hierarchy in the Supplier item List and click 'Unpublish' and confirm which retailers you want to unpublish from when prompted (if both or all levels of your hierarchy are marked as Orderable and show Published instead of Sent in the Overall State Column, tick both and 'Unpublish').
Step 5: Once your item has been unpublished, the final step is to 'Release' the new GTIN or Hierarchy and 'Release' the price (resulting in auto-publication).
You have now completed the process!