The most reliable way to track mileage is with a dedicated app. MileIQ, Everlance, and Stride all run in the background on your phone and detect when you’re driving. At the end of each trip, you classify it as business or personal with a quick swipe. This takes seconds compared to trying to remember trips at the end of the week or month.

Whatever method you use, the IRS wants to see four things for every business trip: the date, the starting and ending locations, the business purpose, and the miles driven. Most apps capture all of this automatically. If you’re using a paper log or spreadsheet, you need to write it down after every single trip. Most people don’t stick with manual tracking for long.

Track every business mile, not just the long ones. Driving from one client to another counts. Running to the supply store for materials counts. Going to the bank to deposit checks counts. These short trips add up fast. At the current IRS mileage rate of 67 cents per mile, missing just 50 miles a week costs you over $1,700 in deductions annually.

Your commute from home to your first job of the day generally doesn’t count as business mileage. But once you’re at that first job, every mile you drive to the next client, to pick up supplies, and back home at the end of the day can qualify. The rules around this get specific, so track everything and let your bookkeeper near Gentry help you categorize correctly.

You have two options for claiming the deduction: standard mileage rate or actual expenses. Standard mileage is simpler. Multiply your business miles by the IRS rate and that’s your deduction. Actual expenses requires tracking gas, maintenance, insurance, repairs, and depreciation, then calculating the business-use percentage of your vehicle. For most home service businesses, standard mileage is easier to maintain and often results in a larger deduction anyway.

Reconcile your mileage monthly. Check that your app recorded trips correctly and that you classified them accurately. It’s much easier to remember if that trip to Bentonville was business or personal when it happened last week rather than eight months ago at tax time.

Keep your mileage records even after you file your return. The IRS can audit returns for up to three years, sometimes longer. Your app should let you export reports, or save your log somewhere you won’t lose it.

The biggest mistake is not tracking at all or trying to reconstruct mileage in April. You’ll either underestimate and lose deductions, or overestimate and risk problems in an audit. Five minutes a week reviewing your mileage saves hours of stress later and puts real money back in your pocket.