[proamdev123]

The workaround for many to many relationships isn’t too hard.

What you have to do is create another table containing unique values of items sold, and then make 1:many relationships from that table to the other two. You can easily make the unique value table by copying and pasting all of the items sold into a single column on a new sheet, highlight them all, and then Data -> Drop Duplicates. It’s a little annoying, but not hard.

[jimnotgym]

But I have line level data that needs summing in the sales table. The workaround is one table of stock, one of sales and a sumif on the sales to get the stock. But now I don't have a pivot table

[proamdev123]

That’s what Power Pivot is for. Once you create the additional table and relationships as I described, you should be able to create a pivot table using data from multiple tables. No SUMIFs required. Unless I’m misunderstanding something.