When creating a listing on Amazon UK, you are presented with two inventory tracking options: Manufacturer Barcode (Commingled) or Amazon Barcode (FNSKU).
What is Commingled Inventory?
With commingled inventory, Amazon pools products with the same EAN/UPC from multiple sellers into a shared inventory bin. When a customer orders from your store, Amazon picks any unit from the bin closest to the customer—even if that unit was sent by a totally different seller.
The Dangerous Hidden Risk
If another seller sends in counterfeit, expired, or defective products under the same EAN, their faulty unit might be sent to your customer. You receive the negative review, return defect rate, and potential account suspension for inauthentic goods.
The Solution: Unique FNSKU Labeling
Applying an FNSKU ensures that only the exact items prepped and verified by your prep partner are shipped to your buyers. This protects your seller metrics and Buy Box performance.