Schedule C (Form 1040), Profit or Loss From Business, is the IRS form a sole proprietor uses to report the income and expenses of a business, producing the net profit or loss that carries to Form 1040.
The IRS treats an activity as a business when your primary purpose is income or profit and you’re in it with continuity and regularity — a weekly points chase clears that bar more easily than four shows a year. Part I is income: purse, points fund, contingency, tow money, sponsorship. Part II is expenses, with car and truck on line 9, and Part V catches other expenses that don’t have their own line. Net profit flows to Schedule SE, where self-employment tax runs 15.3 percent — 12.4 for Social Security, 2.9 for Medicare — once net earnings reach $400. General education, not tax advice; have a tax professional check your first one.
Filing Schedule C is what turns a race operation from a taxable-winnings hobby into a business that can deduct its costs, and what puts those deductions on the record if the IRS ever asks.