Hi All

I understand that VAT is calculated per line item for a given invoice and then is rounded to 2 decimal places and I can calculate this correctly by hand.

However when I add a X percent (in my case 2) discount on my invoice no matter how I calculate the VAT (so 20% of the 2% on the discount amount, or 20% of the 2% per line item pre quantity, 20% of the 2% per line item post quantity...) I cannot calculate the same number..

I have multiple invoices and no matter what I do some methods work for some but not for others to calculate correectly.

Does anyone know the correct way discount percentages are applied to invoices? Invoices are entered ex vat. 

Many Thanks