Uploading items catalog descriptions and inventory in bulk via CSV is a multi-step process that involves working with two different types of CSVs which are "Items descriptions" and "Items inventory".
The first step is to create and import "Items descriptions" CSV in order to create new items or update existing items in SKULabs. A SKU should only occur once in the "Items descriptions" CSV because it is required unique for each item.
Once the "Items descriptions" CSV upload has completed, verify that the items are created as you expected by refreshing the page and navigating to: Inventory page > Items tab.
The next CSV to be uploaded is the "Items inventory" CSV, which requires Warehouses and Locations names for each SKU you want to uplaod stock quantities to. Therefore, make sure that all of the Warehouses and Locations names you want to include in the "Items inventory" CSV already exist in SKULabs. To do this, go to Inventory page > Warehouses tab to see the list of Warehouses and open a warehouse to see the list of locations in that warehouse. If you need to create warehouses or locations, do so before building the "Items inventory" CSV.
Next, create and import "Items Inventory" CSV. The best place to start, particularly if you already have inventory quantity data in SKULabs, is to first Export "Items inventory" CSV. Exporting "Items inventory" CSV is very important for two reasons. 1, You will have a backup of your inventory data that will be very handy for easily restoring your data just in case a mistake happend. 2, "Items inventory" CSV Export is compatible with the "Items inventory" CSV Import and makes for a very good starting point instead of starting from scratch.