McDonalds organises a customer satisfaction survey in the name “MCDVoice” at the official site www mcdvoice com. Customers who dine-in at McDonald’s restaurant will receive a printed receipt soon after the purchases. This McDonalds Survey code on printed receipt is mandatory in-order to take www mcdvoice com survey . After you complete your mcdvoice survey, win free sandwich upon purchase of any sandwich on your next visit.