Final tax income refers to the amount of income on which tax is fully settled at the source or through a specific tax rate, meaning the taxpayer does not have to pay any additional tax on that income when filing their tax return. It is a fixed tax applied directly, and no further assessment or adjustment is required.For example, certain types of income like interest from bank deposits or dividends might be subject to a final tax, where the tax deducted is considered the full and final tax liability on that income.