By default, SKUs in Zentail are sent into Amazon as "Merchant Fulfilled" (aka "MF", aka "FBM").
When you start fulfilling with FBA, you will need to decide if you would like to create a new SKU value for the FBA version of a given product, or if you would like Zentail to communicate your existing SKU as an FBA SKU in Seller Central.
Because Amazon does not allow you to sell your FBA and FBM inventory under the same SKU value, if you want to be able to list both sources of inventory at the same time, you will need to have two separate SKU values; one for FBA, one for FBM. To simplify this, we "merge" your FBA and FBM SKUs in Zentail so you only interact with one SKU in Zentail, and on the back end we communicate with both SKUs in Seller Central.
Some major benefits of merged SKUs:
you manage one SKU in Zentail instead of two separate SKUs for a given product.
you can see how much inventory you have in each warehouse.
you can make your FBA and FBM inventory available to other channels which only accept one unique SKU value per unique identifier/condition pair (i.e. UPC, EAN)
Here's how to convert a SKU from a "Single" (FBM) status to FBA:
To summarize this action, Zentail now communicates this SKU as an FBA SKU with Seller Central and the SKU in Seller Central is switched from Merchant Fulfilled to FBA. Zentail will also create a new FBM version in Seller Central using +MF+ convention. You will not see the +MF+ SKU in Zentail except in the Amazon card on the SKU overview for the SKU you just converted to FBA.
This action only changes how your SKU is communicated with Amazon.