Once you have added the products you wish to purchase to your cart, you can enter the discount code in the dedicated section on the check-out page. Once you have entered the discount code, click on "apply": the total cost of your order will be automatically updated, applying the discount. Warning: remember to apply the discount code before paying your order! Once your order has been confirmed, you will not be able to change it.
Discount codes cannot be combined. Also, they do not apply on mini sets, items already discounted in the "Sales" section or special edition products, like the Advents Calender.