basically as it says - the VAT/Tax is being calulated on the sub total but I want to have tax/VAT caluclated on the subtotal AFTER the group discount is taken off

I have read through 100's of threads and made the changes to ot_group_pricing.php but still doesn't nopt work - I think that the ot_tax file needs some editting so that it takes the discounts into account before applying tax - but that file is beyond me!

so I have this:

Sub-Total:£40.00
Flat Rate (Best Way):£9.95
Discount Coupon: FREESHIPPING :-£9.95
Group Discount:-£3.00
VAT @ 17.5%:£7.00
Total:£44.00

Now the VAT or Tax should be 17.5% of subtotal-group discount - ie £37

I can change the orders and tax yes/no on group pricing to get the total figure correcT BUT for VAT purposes I actually ned the VAT to say £6.475 not £7 and that I cannot figure out

Anyway ideas?

Its almost like we need a second sub total after discount? and then apply Tax/VAT to that?

thanks
Sarah