Display the total value of discount give at the end
After applying the discount at the transactional level. The total discount given should be displayed at the bottom and then the taxes have to be calculated on the discounted prices.
I agree! There should be a line item showing total discount on the invoice even when the discount is given at line item level.
This shows the customer the value of the total discount we are giving on the total rrp invoice.
As discounts are applied at line item level then perhaps at the bottom it could say:
Subtotal (includes a discount of 1,569.78)
This is what Xero does.