Legal analysis: Taxpayers determine whether the sales of postal services, telecommunications services, modern services and life services account for more than 50% in a certain time interval. For the special case that the taxpayer's sales within the above range are zero, the announcement clarifies how to apply the additional deduction policy.

Legal basis: Article 15 of the Provisional Regulations of the People's Republic of China on Business Tax, the tax payment period of business tax is 5 days, 10 days, 15 days, 1 month or 1 quarter respectively. The specific tax payment period of taxpayers shall be determined by the competent tax authorities according to the tax payable of taxpayers; If the tax cannot be paid within a fixed time limit, the tax can be paid on time. If a taxpayer takes 1 month or 1 quarter as a tax payment period, it shall file a tax return within 15 days from the expiration date; If the tax period falls on 5th, 10 or 15, the tax shall be paid in advance within 5 days from the expiration date, and the tax shall be declared within 5 days from 1 the following month.