Subparagraph 3, Paragraph 1 of Article 17 under the Consumer Protection Act states that central government authority may request traders to provide performance guarantee for prepaid transactions. By restoring the mechanism of arbitrary guarantee (the concurrent performance counterplea and post-performance payment), consumer disputes resulting from involuntary bankruptcies have greatly decreased. In addition, regarding a variety of standardized contracts, the foregoing Act and the Supreme Court have allowed consumers to terminate a continuous or continuous supply consumer contracts at any time. This not only protects consumers’ moral rights but also frees them from the loss of arbitrary guarantee. Under German law, a general provision excluding or restricting concurrent performance counterplea to the extent that the function of guarantee has almost lost will generally be deemed void with only a few exceptions. With this control of content, consumer may even seek repayment for the transaction amounts or remunerations, forcing traders to provide more consumer-friendly standardized contracts. The purpose of this Article is to make a great effort to present the Consumer Protection Act’s regulatory design for prepaid transactions and the relationship between the said Act and the Civil Code.