First, make sure that you enter the code in the correct place. A gift card is a payment method. This means it must be entered at the payment step in the ordering process. This is the step where options like 'iDeal' or 'Credit card' can also be selected. 

This is a different place than where the discount code should be entered. That is already at the step of entering your details.

Still unable to redeem? Please check the following:
1. Have you correctly entered the gift card code? The 19 digits without spaces.
2. Are you using the PIN code (under the scratch layer) on the back of the gift card?

If it still does not work, please contact customer service. We are happy to help you.