Troubleshooting article: When changing inventory from MF to FBA within Amazon, you may run into issues if proper steps are not taken. If a seller is attempting to change an item from MF to FBA, you will need to follow the steps below to properly add another SKU to change from MF to FBA.
Log into Amazon Seller Central
Select "Inventory" tab at top of page >> Manage Inventory
Find the SKU that you would like change from MF to FBA and correlating ASIN. (example SKU: TN-4F0Y-AEL4/ ASIN: B00OPF9HQO)
COMMNON PITFALL >> clicking "edit" on an item and selecting "change to fulfill by Amazon" | This will cause more harm than help, please DO NOT click this option
Select . "Inventory" tab at top of page >> "Add a Product"
Enter ASIN of product (example: B00OPF9HQO)
Select "Sell Yours"
For the SKU, enter the identical SKU from the product (TN-4F0Y-AEL4) this time we will add the -FBA suffix at the end of the SKU. (example: TN-4F0Y-AEL4-FBA)
Select "Advanced View" over to the right hand sideSelect "I want Amazon to ship and provide customer service for my items if they sell."
Select "Save and Finish"Listing Mirror will now pull in this new listing data from Amazon and it will be viewable from the "Amazon" tab within Listing MirrorSelect "Manage Duplicate Listings"
You will be able to see both SKU's (original SKU vs. original SKU-FBA)