Value-added and Non-value-added Business Tax Act Article 17
In the event that a business entity sells goods or services at a price significantly lower than the market price with no proper reason, the competent tax authority may determine the sales amount based on the market price.
中文原文 加值型及非加值型營業稅法第17條
營業人以較時價顯著偏低之價格銷售貨物或勞務而無正當理由者，主管稽徵機關得依時價認定其銷售額。