Last Tuesday you drove to three client meetings, swung by the office-supply store, and headed home. Come tax time you half-remember it as "a lot of driving," so you write down a number that feels honest. That guess is exactly the kind of thing that gets thrown out the second anyone looks closely. The car deduction is one of the bigger write-offs available to self-employed people, and claiming it right comes down to two decisions and one habit.

The two methods, and why you usually pick one

The IRS gives you two ways to deduct the cost of driving for business. The standard mileage method multiplies your business miles by a per-mile rate the IRS sets each year. In recent years that rate has hovered in the high 60-cents range; it shifts annually, so look up the current figure before you file. The actual expense method adds up what the car genuinely costs you — gas, oil, insurance, repairs, registration, tires, lease payments or depreciation, all of it — and lets you deduct the business-use share of that total.

Picture 10,000 business miles in a year. At roughly 67 cents, standard mileage hands you about a $6,700 deduction, no receipts required. Run the same year on actual expenses and maybe your real costs came to $9,000; if 60% of your driving was for business, you deduct $5,400. Same car, two answers. Which one wins depends almost entirely on the car and how hard you drive it.

Which method actually saves you more

Standard mileage favors high-mileage drivers in a reasonably efficient, paid-off car. The rate is generous, and you skip the receipt-hoarding. Actual expenses pull ahead when the car is expensive, the lease is heavy, or the year brought big repair bills — anything that pushes your true per-mile cost up.

A rideshare driver logging 25,000 business miles in a used Corolla will almost always come out ahead on standard mileage. A consultant leasing a $55,000 SUV who drives it 4,000 business miles a year usually does better on actual expenses, because that lease payment and insurance swamp whatever the mileage rate would return.

Here's the catch that trips people up. To keep standard mileage on the table for a car you own, you generally have to choose it the first year that car goes into business service. Start with actual expenses in year one and you can lock yourself out of standard mileage on that vehicle for good. Leased cars carry their own twist: go standard mileage on a lease and you're committed to it for the whole lease term. When real money rides on the choice, run both calculations or ask a tax pro before you commit.

What actually counts as a business mile

A business mile is driving you do for work, between business destinations, after your workday has started. The clean cases:

  • From your home office to a client's location and back.
  • From one job site to a second.
  • A run to the bank for a deposit, the post office to ship an order, or the supply store for materials.
  • Out to meet a prospect, or to a conference tied to your trade.

If you have a qualifying home office — your principal place of business — the math turns friendlier, because trips from home to a work location count as business miles instead of commuting. That one quirk is a quiet reason the home office deduction is worth setting up properly.

Why your commute is not deductible

Now the blunt part. The drive from your home to your regular place of work is commuting, and commuting is personal — never deductible, no matter that you're self-employed and it sure feels like work. As far as the IRS is concerned, getting yourself to your job is your problem, not the government's.

The in-between trips are where people slip. Home to your regular workspace is commuting. Once you're working and you drive to a client across town, that leg is business. Drive home from the client and the final leg flips back to commuting. Stopping for a quick business errand on the way home doesn't launder the whole trip into a deduction — only the genuinely business portion counts. And slapping a magnetic logo on your door turns nothing into a write-off; that myth has cost people in audits.

The records that hold up

This is the habit that makes everything above real. A deduction you can't document is a deduction you lose if questioned, and "I drive a lot for work" is not documentation. For each business trip, keep a log with the date, the destination, the business purpose, and the miles driven. Jot your odometer reading at the start and end of the year too, so you can show total miles — the IRS wants your business miles as a slice of all your miles.

None of this requires a leather-bound diary. A mileage app running quietly in the background, a spreadsheet you update on Fridays, a notebook in the glovebox — any of them work, as long as it's contemporaneous, kept around the time you actually drove rather than reconstructed from memory in April. Going the actual-expense route? Hang onto the receipts and statements: gas, insurance, repairs, the lease or purchase paperwork.

The percentage ties it all together. Say you drove 18,000 miles this year and your log shows 7,200 were for business. That's 40% business use. On actual expenses, you deduct 40% of your car costs. On standard mileage, you take 7,200 times the current rate. Either way, that 7,200 has to stand behind a log.

A few traps and edge cases

The ones that quietly catch people:

  1. No double-dipping. Standard mileage already bakes in gas, depreciation, and maintenance, so you can't deduct those again on top of it. Business parking and tolls you can add to either method.
  2. Switching methods has limits. After you've used standard mileage on a car, you can usually move to actual expenses later, but depreciation then gets figured a particular way. Doable, just not casual.
  3. Personal miles stay out. The grocery run, the kid's soccer practice, the weekend road trip — none of it counts, and padding your business percentage is the fastest way to make a clean return look shady.

Run the numbers both ways your first year if you can, then keep an honest log going forward. The deduction is large enough to justify fifteen real minutes a week. To see how the write-off folds into your wider self-employment tax picture, our calculators can help you estimate the impact before you file.

This is general educational information, not personalized tax or legal advice. Tax rules and mileage rates change, so confirm current figures and your own situation with the IRS or a qualified tax professional.