[EDIT 27/5/09: The Tech Team have asked me to make clear that CTO does now support all OSCommerce Voucher & Coupon contributions in the known universe... although if you have an unknown one, we're happy to add it!]
It may be a Bank Holiday Weekend, but we are hard at work bug fixing and improving CTO in preparation for the launch on May 5th.
We expect the discounts bugfix to be implemented by Monday.
Currently CTO does not support discount coupons or vouchers. It would be impossible to support all the myriad voucher contributions out there for OSCommerce.
Instead, what we're doing is taking the total order value and subtracting the amount paid. Anything left over is a discount or coupon.
By default, the discount will show VAT - so a £10 voucher is £8.70 + VAT.
However, if you have a situation where you sell £300 of baby clothes (zero rated for tax) and charge £5 plus 75p VAT for delivery, and provide a 50% discount, the VAT on the discount will be the maximum VAT charged on the order.
Baby Clothes: £300
After applying a 50% discount, the total paid is £152.88.
The discount line on KashFlow would show it as: £152.13 + 75p VAT, so it would look like:
Baby Clothes: £300.00 + £0.00 VAT
Delivery: £5.00 + £0.75 VAT
Discount: -£152.13 - £0.75 VAT
Total: £152.88 + £0.00 VAT