Stranded inventory is FBA inventory in fulfillment centers that does not have an associated active offer and thus is not available for sale on Amazon. When inventory is stranded, it requires either reactivating the listing or removing inventory.
Amazon will notify you about stranded inventory in three ways:
When you delete or close a listing, or change it from Fulfilled by Amazon to Fulfilled by Merchant, it might strand your inventory. Product listing issues, infringement concerns, or system errors can also result in stranded inventory.
For a complete list of reasons for stranded inventory, see Resolve stranded inventory issues.
If there is lost inventory at the fulfillment center, or if there are customer returns of an item without an active offer, this inventory will be stranded.
If the quantity column is populated in the Bulk upload template, such as Inventory Loader, listings change from Fulfilled by Amazon to Fulfilled by Merchant automatically, which strands your inventory.
Additionally, if you do not fill out the Is this product a battery or does it require batteries? column, it might strand your inventory in some categories.
When you create a new or revise an existing listing, make sure the values for ASIN, SKU, and condition are the same as those in your stranded inventory list.
Include all vital information for a listing before sending a shipment, including the brand, category, price, and condition.
To learn more about fixing your stranded inventory, watch this Seller University video.