When you upload an inventory file, you can use the Purge and Replace option to remove your current inventory and replace it with the inventory in the file. The listings that are not in the file will be removed from the Amazon web site. If you upload an empty inventory file with Purge and Replace selected, all your listings will be deleted.
We recommend that you request and download an Active Listing Report before using the Purge and Replace option. The Active Listings Report provides a good basis for reviewing your existing inventory records and can also serve as a backup file in case there is an error in the file you send when you perform a Purge and Replace.
There are some good cases for using the Purge and Replace option.
Delete your entire inventory to start from scratch
If you need to remove and replace your entire inventory, you can upload an empty feed with just the headers and Purge and Replace option selected. This enables you to delete all your listings.
Use different SKUs to reference your products
If you decide to change the SKU naming convention you use to reference your products, you can use the Purge and Replace option to do this. However, you cannot use the Purge and Replace option to change your SKUs in the following two cases:
In general, it is not recommended to use the Purge and Replace option to routinely manage your inventory levels. Use the Purge and Replace option sparingly and for special cases where you need to start from scratch with new inventory counts or need to make changes to your SKU-naming conventions.
Specifically, we don't recommend using Purge and Replace to perform the following tasks:
Disabling out-of-stock offers
Synchronizing your product database with your Amazon product listings
Although it is not recommended, you may use the Purge and Replace option to keep the products you list on Amazon synchronized with your own product database. The risk with this practice is having an error in your inventory file or uploading the wrong file, which may potentially erase your entire inventory on Amazon. This could result in lost sales opportunities while you re-list your products.
We recommend that you explicitly delete a product from your inventory only if you know that you are never going to sell that product again. If you are just temporarily out of stock, do not delete the product but do set the quantity to zero (0).