A fraud prevention system has a customer sign-up program accessible via a computer network that functions to receive an inquiry from a customer. A phone number database enables confirmation of a phone number provided by the customer. A validation program generates a validation page having a text receiving box adapted for receiving an inputted PIN, calls the phone number to establish phone communication with the customer via a phone service, provides a PIN via the phone service, receives an inputted PIN via the validation page, and confirms that the inputted PIN matches the PIN provided via the phone service. Finally, the validation program updates the phone number database so that the phone number is no longer valid, and provides credit to the affiliate for referring the customer.