@alwayspaws The Reference column is the sku for the combination. I use the product reference number-#. For instance, if my product sku (product reference number) is SG201 and I have 4 combinations for that product then the reference column would contain SG201-1 SG201-2 SG201-3 SG201-4. Looking at your spreadsheet it looks like you have that in the product id field. You should have your TB product ID (the number in the first column of your product list in the back office) in that column.