if you are self-employed, and your business is active (you are running it as an ongoing business with a profit motive, you have income or expenses) then you file schedule C with your tax return to report your income, expenses, and pay tax on any net profit. You must report your income from your own accurate records, even if you don’t receive tax paperwork from your clients or customers. You might have taxable income on paper, even if you didn’t withdraw cash from the business to spend for yourself. if your expenses were more than your income, you want to put that loss on paper because you can deduct it against future income.