If you use a vehicle for business, you can deduct the cost of that business use. The IRS gives you two ways to calculate the deduction: the standard mileage rate or actual vehicle expenses. Choosing the right method can mean a difference of hundreds or thousands of dollars per year, and the rules around which method you can use have changed more than most people realize.
Method 1: Standard Mileage Rate
The IRS sets a standard mileage rate each year. For 2024, it’s 67 cents per business mile driven. You track your business miles, multiply by the rate, and that’s your deduction. Simple.
Example: You drive 15,000 business miles in 2024. Deduction = 15,000 ? $0.67 = $10,050.
The rate accounts for all the costs of operating a vehicle: fuel, depreciation, maintenance, insurance, tires. You don’t separately deduct those items. You can, however, still separately deduct business parking fees and tolls on top of the standard mileage rate.
Method 2: Actual Expenses
You calculate the total cost of operating your vehicle for the year, then multiply by the percentage of miles driven for business.
Qualifying actual expenses include:
- Gas and fuel
- Insurance
- Maintenance and repairs (oil changes, tires, brakes)
- Registration fees
- Depreciation (or lease payments if you lease)
- Car washes
- Parking and tolls (business-related)
Example: Total annual vehicle costs = $14,000. You drove 20,000 miles total, 12,000 for business (60% business use). Deduction = $14,000 ? 60% = $8,400.
In this case, the standard mileage rate would have given you 12,000 ? $0.67 = $8,040 ? slightly less. But results vary significantly by vehicle type.
Which Method Wins in Different Scenarios
High-Mileage, Fuel-Efficient Car
The standard mileage rate typically wins. Your actual costs per mile are low (good gas mileage, lower maintenance), so the fixed IRS rate of 67 cents per mile builds in more deduction than you’d get from actual expenses.
Heavy SUV, Truck, or Luxury Vehicle
Actual expenses may win, especially in the first few years when depreciation is highest. A $55,000 SUV that’s 80% business use generates significant depreciation deductions that can far exceed the mileage rate. Section 179 and bonus depreciation can accelerate this even further.
Leased Vehicle
Both methods are available, but there are income inclusion rules for leased vehicles (the “lease inclusion amount”) that partially offset the deduction for higher-value vehicles. Run the numbers both ways before deciding.
The Critical Rule: Method Lock-In
This is the part most people don’t know. If you use the standard mileage rate in the first year you use a vehicle for business, you can switch to actual expenses in a later year. But if you use actual expenses in the first year, you’re locked into actual expenses for the life of that vehicle ? you cannot switch to standard mileage later.
This asymmetry matters. When you put a new business vehicle in service, think carefully about the first-year method.
The Recordkeeping Requirement
Regardless of which method you use, the IRS requires a contemporaneous mileage log. That means you record the information at or near the time of each trip ? not reconstructed from memory months later.
Your log should include for each business trip:
- Date
- Destination (address or business name)
- Business purpose
- Miles driven
- Odometer reading at start and end (or just miles driven per trip)
Apps like MileIQ, Everlance, and TripLog automate this by using your phone’s GPS to detect trips. You categorize each trip as business or personal. At year-end, you have a compliant mileage log.
Common Mileage Mistakes
Claiming 100% Business Use Without Documentation
The IRS scrutinizes 100% business use claims heavily. If you have only one vehicle and no other transportation, auditors question how you ran personal errands. If your vehicle truly is 100% business use (a work van you never drive personally), document it carefully.
Commuting Miles
Miles from home to your regular office are commuting miles ? not deductible under either method. However, if you have a qualifying home office, your home is your principal place of business, and trips from home to client locations or other business destinations are fully deductible business miles.
Reconstructing Records at Year-End
The IRS disallows deductions supported only by reconstructed logs. Use an app or keep a physical log throughout the year. A mileage log prepared in December from memory provides weak documentation.
Section 179 and Bonus Depreciation for Vehicles
If you buy a vehicle for business use, you may be able to deduct a significant portion of the purchase price in the year of purchase using Section 179 expensing or bonus depreciation. This is especially powerful for heavy vehicles (SUVs, pickup trucks over 6,000 lbs GVWR) because they’re exempt from the “luxury auto” depreciation caps that limit deductions for lighter vehicles.
These rules are complex and change year to year. If you purchased or are planning to purchase a business vehicle, book a call before year-end so we can model the depreciation options.
