Hi Jack,
Did you try Double Clicking on the bottom left corner of the cell you want to copy. If you place you cursor on that corner until it turns into a +, you can then double click the plus and it will copy all the way down.
Hi Robbie,
see the attached file, I have tried to make all the parameters dynamic, so you can change the split. The formulas are in the highlighted cells
kanti
Hi Sambit,
I have included a vlookup formula in your file. Please note that the invoice numbers on the sales data tab are formatted as text and not numeric