Gift cards can be redeemed in the final step of checkout and are not discount codes. So don’t worry if your code isn’t accepted at first — you’re probably trying to enter it in the discount code field. In the first step of the basket, you’ll see a note saying that gift cards can only be entered in the next step. If you have a discount code, you can enter it there. Otherwise, simply click Continue.
You should then be able to enter your details on the left and your gift card code on the right.
Important: Before completing your order, please make sure the gift card has actually been applied and the value has been deducted from your total. Gift cards can only be redeemed during checkout and cannot be applied afterwards.