Tax not taking Gift Certificate into account

Hi all,

I've searched the forum, but any answer to this is well hidden.
My checkout calculations are working fine, except when a gift certificate is applied to the cart. Then, all the maths is correct, including final total, however the VAT figure is as if no gift certificate was applied.

Example:
Subtotal 252.17
Gift Voucher -5.00
Discount 5% -12.36
Shipping 3.48
VAT 17.5% 36.20

Total 238.29

The VAT should show 35.49 (VAT on 238.29)

It's actually showing VAT on 243.04, which comes from:

(252.17-12.61(the 5% discount, ignoring the GV)+3.48)=243.04

So, I guess I have 2 questions:

1. How, and where, is tax calculated, and

2. How do I fix it?

Thank you, for any light you can shed,

Regards,

Sean

Hi,

Gift Voucher redemption is not subject to VAT.

Think of the redemption as another form of payment.

...doh.

So, I can't apply the GV before the discount.

Sean