Search for the flight route and dates that you need for your travel plans. Select the flight that you would like to be on, and add on anything extra, such as hold luggage or extra legroom. When you are happy with your choices, head to the payment section of the process. In the review section, you will be given the opportunity to look over the Vueling flights that you have chosen and ensure they are correct. When prompted, paste your Vueling discount code into the promo code box and hit apply. You should now see the subtotal of your booking reflect the discount that you have selected.