The tax collection rate is determined by the tax authorities after investigation. In the case that the taxpayer cannot provide information such as the tax object and tax basis stipulated in the tax law because of the imperfect financial accounting system, the proportion of tax payable is calculated according to other data related to the tax object and tax basis. Usually, because the verification of value-added amount and income is very complicated, the method of multiplying sales income or operating income by the collection rate is used to directly collect taxes.