Group 1 - The article discusses the tax deduction policies for corporate income tax, emphasizing that both internal and external vouchers can be used for tax deductions, not just invoices [2][3] - It clarifies that if a company estimates costs in 2025 but does not obtain invoices by December 31, it does not need to adjust the income tax return as long as the vouchers are obtained by May 31, 2026 [3][4] - The article states that if a company did not deduct expenses in previous years due to lack of vouchers, it can still deduct those expenses in the current year if it obtains valid vouchers, with a maximum retroactive period of five years [5][4] Group 2 - The article outlines the basic regulations for deducting advertising and promotional expenses, allowing deductions up to 15% of annual sales revenue, with excess amounts carried forward to future tax years [10][12] - It specifies that for certain industries, such as cosmetics and pharmaceuticals, advertising and promotional expenses can be deducted up to 30% of annual sales revenue, with similar carry-forward provisions [12] - The article notes that tobacco companies are not allowed to deduct advertising and promotional expenses when calculating taxable income [12]