The collection authority shall, after receipt of an annual income tax return, appoint a person to make investigation thereof and determine the amount of income and tax payable.
Where there is great number of taxpayers in a locality, the collection authority may, in lieu of individual investigation as provided in the preceding Paragraph, conduct random checks by trade and determine the income standard of each trade.
Where the amount of income reported by a taxpayer is above such standard, the reported income shall be taken as the basis for taxation. However a taxpayer who is found by the collection authority to have reported his or her income unusually or with any under-reporting, omission or evasion of the taxable income, or income reported as lower than the standard set forth in the preceding Paragraph shall be subjected to an investigation.
Opinions of trade associations may be sought in determining income standards of taxpayers in the various trades.
The measure governing how the collection authority conducts an assessment of an income tax return by paper reviewing, auditing or any other method of investigation, as well as the criteria governing how the aforesaid authority audits the items affecting the amounts of income, tax payable and tax credits of an income tax return, shall be prescribed by the Ministry of Finance.