IRS Schedule C “Profit or Loss From Business” Explained

IRS Schedule C, Profit or Loss From Business (Sole Proprietorship), is the schedule self-employed individuals attach to their Form 1040 to report business income and expenses. The net profit or loss from Schedule C is included in your income and is also the starting point for self-employment tax.

Who Files Schedule C?

• Sole proprietors and independent contractors, including freelancers, consultants and gig workers
• Owners of single-member LLCs that haven’t elected to be taxed as a corporation
• Statutory employees reporting wages and expenses
• Spouses who each run a qualified joint venture

If you received Form 1099-NEC or Form 1099-K for work you did as a business, that income usually belongs on Schedule C. Farmers use Schedule F instead.

The Parts of Schedule C

• Part I, Income: gross receipts, returns and allowances, cost of goods sold and other business income
• Part II, Expenses: advertising, car and truck expenses, contract labor, insurance, interest, legal and professional fees, office expenses, rent, repairs, supplies, taxes and licenses, travel, 50% of qualifying business meals, utilities, wages, depreciation and more
• Part III, Cost of Goods Sold: for businesses that sell products, including inventory at the start and end of the year
• Part IV, Vehicle Information: business miles and records for vehicles you’re deducting
• Part V, Other Expenses: deductible business expenses that don’t fit the lines in Part II

Home office costs are figured on Form 8829 (or with the simplified method) and carried to Schedule C. Vehicle costs can use the standard mileage rate or actual expenses. See IRS Automobile Tax Deductions Explained.

Where the Numbers Go

• Net profit or loss flows to Schedule 1 and then to Form 1040.
• If your net earnings from self-employment are $400 or more, you’ll also file Schedule SE and pay self-employment tax (Social Security and Medicare). That tax is reported on Schedule 2.
• Qualified business income may also be eligible for the qualified business income (QBI) deduction.

Common Schedule C Mistakes

• Not reporting all income, including cash, card and app payments
• Deducting personal expenses or claiming 100% business use of a vehicle without mileage logs
• Mixing business and personal bank accounts, which makes expenses hard to prove
• Skipping quarterly estimated tax payments and then owing penalties
• Showing repeated losses on an activity that may be treated as a hobby

Good records are your best protection if the IRS questions your return. Keep receipts, invoices, bank statements and mileage logs for at least three years after filing. For more planning tips, see Small Business Tax Preparation: 6 Essential Tips and our small business tax preparation services.

Get Help From Diehl CPA

Tax rules change often, and the right answer depends on your full financial picture. Diehl CPA, led by Mark Diehl, CPA, CFE, prepares returns and builds tax plans for investors, retirees and closely held businesses. Learn about our tax return preparation and investment tax planning services, or contact us to talk through your situation.

This article is general information, not tax or legal advice for your specific situation. Updated October 2026.