For self-employed workers and 1099 contractors, the mileage deduction is one of the most valuable tax breaks available. The choice between standard mileage rate and actual expense method has significant long-term implications — and once chosen, the rules limit your ability to switch.

Who Can Claim

Mileage deductions are available to self-employed individuals (sole proprietors, single-member LLCs, partnerships) and 1099 contractors with business use of personal vehicles. W-2 employees CANNOT deduct unreimbursed mileage under TCJA (2018–2025+). Medical mileage qualifies when transporting yourself or a dependent for medical care; military relocation mileage qualifies for active-duty members with PCS orders. Charitable mileage is deductible at 14¢/mile for volunteer drives. Commuting between home and main business location is NEVER deductible regardless of distance — this is the most common error among first-time deducers.

Standard Mileage vs. Actual Expense — The Critical Choice

The IRS lets you choose between standard mileage rate (per-mile flat rate covering everything) or actual expense method (prorated by business-use percentage). 2026 standard rate is 70¢/mile business. Standard method is simpler and typically wins for: high-mileage commercial vehicles (rideshare, delivery), older paid-off cars (low actual costs), and vehicles with lower depreciation. Actual method typically wins for: newer expensive vehicles with lower mileage, vehicles with high lease payments, and high insurance markets. Run both calculations for your first business use of a vehicle — the choice has long-term consequences described below.

The Switching Rule

IRS rules limit your ability to switch between mileage methods. If you choose actual expense method in the first year of business use, you must continue actual method for the entire ownership of that vehicle. If you choose standard mileage in year 1, you can switch to actual method later if needed (but with adjustments to basis). This asymmetry favors choosing standard mileage in year 1 unless you're confident actual method will produce larger deductions. For business owners who change vehicles every 3–5 years, sticking with standard mileage across all vehicles creates a consistent and audit-friendly pattern. Multi-vehicle scenarios: each vehicle is evaluated independently — you can use standard on one and actual on another.

Substantiation Requirements

The IRS requires contemporaneous documentation of business mileage: date, destination, business purpose, and miles driven. Apps like MileIQ, Stride, and Everlance use GPS to automatically log trips, prompting for purpose at month-end. Manual logs in a calendar or notebook also work but must be detailed. Audit risk increases with: round numbers (15,000 miles flat is suspicious), 100% business use claims for personal vehicles, deductions that exceed industry norms for your business type. Cumulative records: keep odometer readings at start and end of year, monthly mileage totals, and detailed trip logs. Without substantiation, the IRS can disallow the entire deduction. Mileage tracking apps cost $5–$10/month — far cheaper than recreating a year of trips at audit.