Hi there,
I have installed the "edit order" mod, but am having problems with VAT not changing when adjusting the order total.

For instance, on one order of say £100, I promised the customer they could have it at £80 and free shipping as a special one off deal.

I have gone into the order to edit it, and added a "special discount" of -£20 and made the shipping £0.

Doing this has worked, but it has applied the discount after tax, rather than before it, so the VAT is still £17.50 (17.5% of the original £100 bill).

I need the discount to be applied pre-tax. Has anyone any idea how I would do this?

Many thanks.