Discount vouchers are digitally assigned to your account - there is no code to copy and paste!
You can view your vouchers by logging into your account and visiting the 'Voucher Codes & Discounts' page via 'My Account'.
Your voucher will automatically apply to your basket when you get to the 'review' step of the checkout process, but you can remove it at that step should you wish to retain it for a future purchase.
Please bear in mind that vouchers are limited to one use, and some products are excluded from discount such as: subscriptions, bundles, limited edition items, Webshop Exclusives and t-shirts/external merchandise.