Log in to your Tesco account or register if you are new to Tesco Add the products you want to buy to your Shopping trolley and check out your Shopping List On the payment page, there is an E-Coupons section. Enter your E-Coupon code into the textbox and click on ‘Use Code’ button to add your E-Coupon to your Shopping List The E-Coupon discount is automatically deducted from the total of your shopping before you pay.