Broadly speaking, there are three types of chargebacks: merchant error chargebacks, criminal fraud-related chargebacks, and friendly fraud. Chargebacks initiated by consumers in response to merchant errors like billing mistakes or missing goods are legitimate. Chargebacks that reverse unauthorized transactions are also legitimate, even though the transactions themselves were not. However, chargebacks are considered fraudulent when they are filed by consumers against legitimate transactions; a practice that is commonly known as friendly fraud.