Enforcement Rules of the Income Tax Act Article 17-2
Where an individual selling his or her house can present documents certifying the selling price and costs and expenses in the transaction, the calculation of property transaction income shall be verified based on the documents in accordance with Category 7, Paragraph 1, Article 14 of the Act; where the individual fails to declare the above or provide certification documents, the tax authority may determine the income in accordance with the approval standards set by the Ministry of Finance.The standards stated in the preceding Paragraph are to be established by the national tax administration under the Ministry of Finance in all districts by referring to the actual economic condition and trading activities in the house market in that current year, and submitted to the Ministry of Finance for approval.
中文原文 所得稅法施行細則第17-2條
個人出售房屋，如能提出交易時之成交價額及成本費用之證明文件者，其財產交易所得之計算，依本法第十四條第一項第七類規定核實認定；其未申報或未能提出證明文件者，稽徵機關得依財政部核定標準核定之。
前項標準，由財政部各地區國稅局參照當年度實際經濟情況及房屋市場交易情形擬訂，報請財政部核定之。
前項標準，由財政部各地區國稅局參照當年度實際經濟情況及房屋市場交易情形擬訂，報請財政部核定之。