Legal analysis: 1. The formula for calculating the stamp duty payable for the proportional tax rate certificate is: stamp duty payable = tax payable contained in the certificate × applicable proportional tax rate; 2. For vouchers with fixed tax rate, the calculation formula of stamp duty payable is: stamp duty payable = number of taxable vouchers × trial unit tax amount.

Legal basis: People's Republic of China (PRC) Tax Collection and Management Law.

Article 1 This Law is formulated with a view to strengthening the administration of tax collection, standardizing tax collection, safeguarding national tax revenue, protecting the legitimate rights and interests of taxpayers and promoting economic and social development.

Article 2 This Law is applicable to the collection and management of various taxes collected by tax authorities according to law.

Article 3 The collection, suspension, reduction, exemption, refund and supplementary payment of taxes shall be carried out in accordance with the law. Where the State Council is authorized by law, it shall be implemented in accordance with the administrative regulations formulated by the State Council.

No organ, unit or individual may, in violation of the provisions of laws and administrative regulations, arbitrarily make decisions on tax collection, suspension, tax reduction, exemption, tax refund, overdue tax and other decisions inconsistent with tax laws and administrative regulations.

Article 4 Units and individuals that are obligated to pay taxes according to laws and administrative regulations are taxpayers.

Units and individuals that have the obligation to withhold and pay taxes according to laws and administrative regulations are withholding agents. Taxpayers and withholding agents must pay taxes, withhold and remit taxes and collect and remit taxes in accordance with the provisions of laws and administrative regulations.