Form 8288, U.S. Withholding Tax Return, is used to report withheld taxes on payments to nonresident alien individuals and foreign corporations. The tax liability is calculated differently in each part: Part I: Withholding tax on fixed and determinable income (FDI), such as interest, dividends, rents, and royalties. The tax is calculated at a flat rate based on the type of income and the payee's tax treaty status, if applicable. Part II: Withholding tax on wages paid to nonresident alien individuals. The tax is calculated based on the wages paid and the applicable tax treaty rate, if any. Part III: Withholding tax on other types of income, such as commissions, fees, and annuities. The tax is calculated based on the type of income and the payee's tax treaty status, if applicable. It is important to note that the tax rates and rules can change, so it is essential to refer to the current IRS instructions for Form 8288.