Tax & Compliance
Form 1040 attachment where US sole proprietors report deductible expense including vehicle.
Schedule C is the IRS Form 1040 attachment where sole proprietors report business income and expense. Vehicle expense goes on Line 9 (Car and truck expenses). The taxpayer picks either the IRS standard rate (US$ 0.67/mile in 2025) or the actual expense method. The choice is locked for the vehicle's life in many cases. Required substantiation: log with date, miles, business purpose, origin, and destination.