After you have added your products to your basket and are ready to place your order, go to check out and you will see your current rewards balance and have the option to say how much of your rewards you wish to spend. You need at least £2 in your pot in order to spend from it and the maximum you can spend from your pot during one order is £40. You can only spend in pounds rounded down. For example, if you have £7.60 in your pot, you can spend up to £7. You can wait and leave your pot to build up, but bear in mind rewards money expires 180 days after you earnt it.