The amount of basic income of a profit-seeking enterprise shall be the sum of the taxable income as calculated in accordance with the Income Tax Act and such income as may fall under the provisions of the following subparagraphs: 
1. The amount of income exempted due to suspension of income tax in accordance with Article 4-1 and 4-2 of the Income Tax Act.
2. The amount of income exempted from profit-seeking enterprise income tax in accordance with Article 9, Article 9-2, Article 10, Article 15 and Article 70-1 of the abolished Statute for Upgrading Industries.
3. The amount of income exempted from profit-seeking enterprise income tax in accordance with Article 8-1 of the abolished Statute for Upgrading Industries before the revision of December 31, 1999.
4. The amount of income exempted from profit-seeking enterprise income tax in accordance with Article 28 of the Statute for Encouraging Private Organizations to Participate in Transportation Construction.
5. The amount of income exempted from profit-seeking enterprise income tax in accordance with Article 36 of the Act for Promotion of Private Participation in Infrastructures Construction Projects.
6. The amount of income exempted from profit-seeking enterprise income tax in accordance with Article 18 of the Act for Establishment and Administration of Science Parks.
7. The amount of income exempted from profit-seeking enterprise income tax in accordance with Article 15 of the Act for Establishment and Administration of Science Parks before the revision of January 20, 2001.
8. The amount of income exempted from profit-seeking enterprise income tax in accordance with Article 37 of the Business Mergers and Acquisitions Act.
9. The amount of income exempted from profit-seeking enterprise income tax in accordance with Article 13 of the Offshore Banking Act. However, the amount of income allowed for under this exemption does not include the total revenue derived from a credit extension that shall be taxed at the prescribed withholding rate in accordance with Article 73-1 of the Income Tax Act.
10. The amount of income that is entitled to reduction or exemption from profit-seeking enterprise income tax or that is excluded from the income tax base as may be provided for in such laws as may be promulgated after the implementation of this Act and thereafter announced by the Ministry of Finance.
In the case of an amount of income which is added back in accordance with Subparagraph 1 and Subparagraph 9 of the preceding paragraph after this Act coming into force and with the incurrence of a loss which has been assessed by the collection authority, such loss may be offset against income of the same category respectively in the current year and carried forward in the next following five years. 
Where any profit-seeking enterprise sells, starting from the fiscal year 2013, the stocks held for a period of three years or more categorized as the securities regulated in accordance with Article 4-1 of the Income Tax Act, such enterprise, when calculating the amount of income derived from such transactions in the current year, should deduct the losses on the such securities transactions in the same year, and if the previous amount of balance is positive, only one-half of the balance should be added into the current year’s income derived from securities transactions; otherwise, the loss shall apply to the preceding paragraph.
The income which is added back in accordance with Subparagraph 10 of Paragraph 1 and with the incurrence of a loss may apply mutatis mutandis to Paragraph 2 if publicly announced by the Ministry of Finance.