At the 'Information' stage of the checkout, you will see a box below the products you wish to purchase that says 'Gift card or discount code'. Simply enter your discount voucher code and click 'Apply'.
If you are using an Express Checkout payment option, please make sure you apply the discount as above first.
If the voucher hasn't applied to your order and an error is showing, double check that your cart meets the required criteria, and you can contact firstname.lastname@example.org if you require help.
Only one voucher can be redeemed per order.