You can add your Gift Card to your cart on the Your Bag page, which you can access by clicking the Bag icon on the top right-hand side of your screen, before proceeding to check out.
Once successfully added, you will receive a confirmation on your screen.
You only need to apply this once. The value will be held online until you checkout so you can continue shopping and then proceed to the checkout without needing to re-add your Gift Card and pin.
❤ CC xx