Some Burger King coupons can be used for delivery, while others can't. The digital coupons on the app can be used for basically any pickup order. You can also mention them at the window before you pull up. If you're using expired coupons, you probably won't be able to input them into the app or the delivery system. You'll need to take them to the store in person and place an order. If a coupon is valid to use on delivery orders, generally it will be mentioned in the description. For the most part, you should save coupons for times when you're picking up your food yourself.