 Income tax 2023-2024. Business owned and operated by spouses. Get ready and some coffee because the only thing certain in life is death and taxes. And the only thing certain in death is more taxes. Most of this information can be found in Publication 334, Tax Guide for Small Business for Individuals Who Use Schedule C Tax Year 2023, which you can find on the IRS website at irs.gov, irs.gov. Looking at the individual income tax formula basically mirroring the calculation for the Form 1040, the first half of the income tax formula in essence a funny income statement. Most income statements having income minus expenses resulting in net income here having income minus deductions resulting in tax.