Schedule C

Schedule C is where your contracting business meets your personal tax return. It's the form where you report all the money your business brought in (gross income) and all the legitimate business expenses you incurred (materials, tools, vehicle costs, insurance, subcontractor payments, etc.). The bottom line — your net profit or loss — flows onto your Form 1040 and becomes part of your taxable income.

The form itself is straightforward but thorough. Part I covers your gross income. Part II lists common expense categories: advertising, car/truck expenses, contract labor, depreciation, insurance, legal/professional services, office expenses, rent, repairs, supplies, travel, meals, utilities, and wages. Part III handles cost of goods sold (if you sell products), Part IV covers vehicle information, and Part V is for other expenses that don't fit standard categories.

You file Schedule C if you're a sole proprietor or single-member LLC. If you've formed a partnership or S-corp, you'll use different forms (1065 or 1120-S), though the concept of reporting income minus expenses is the same.

Schedule C is essentially the P&L statement for your contracting business that the IRS cares about. Every deduction you claim here directly reduces your taxable income — and your self-employment tax, since SE tax is calculated on your Schedule C net profit.

Keeping clean, organized records throughout the year makes Schedule C painless. Shoebox-of-receipts contractors end up either missing deductions (overpaying taxes) or claiming expenses they can't substantiate (audit risk). Neither is a good outcome.