For private individuals, there may be special promotional offers. If you have a promotional code it should be entered at checkout. Enter the code in the box “Do you have a promo code?” and click “use”, (see image for reference).
The promotional codes are personal and always have an expiration date specified in the discount information for each code.
Please note that you must enter the code when you pay for your order to get the discounted price. A discount cannot be added once your order is completed.