Mileage when you didn't keep a log

The business mileage deduction is one of the biggest deductions available to self-employed people, and one of the most poorly documented. Here's what the IRS actually requires, why a guess doesn't work, and how to rebuild a log it will accept.

What the standard mileage rate covers

For 2026 the IRS business rate is 72.5 cents per mile. That single number replaces tracking gas, oil, tires, repairs, insurance, registration, and depreciation. Drive 10,000 business miles and you deduct $7,250 — no receipts for any of those costs needed.

What it does not replace is proof of the miles themselves. Vehicle expenses fall under a section of the tax code (§274(d)) that says a judge cannot simply estimate a reasonable number the way they can for, say, office supplies. You need adequate records or sufficient evidence corroborating your own statement. No records, no deduction — even if everyone agrees you drove for work.

What counts as business miles

• Driving between job sites, to clients, to suppliers, to the bank for the business
• For gig drivers: miles with a passenger or delivery, and miles between rides while you're logged in and available
• Driving from home to your first stop and from your last stop home — but only if your home is your principal place of business (a qualifying home office)

What doesn't count: commuting from home to a regular workplace, personal errands folded into a work trip, and miles when the app was off.

A reconstructed log is allowed

The IRS accepts a log built after the fact, as long as it's built from evidence rather than memory. The strongest reconstructions combine two or three of these:

• Recurring routes. Home to the job site you go to every Tuesday and Thursday, the supplier you hit weekly. Miles from Google Maps × trips per week × weeks worked.
• App trip history. Uber, Lyft, and DoorDash annual summaries report on-trip miles, and some report online miles. That's third-party evidence, which is the best kind.
• Google Maps Timeline or phone location history. Exportable, dated, and hard to argue with.
• Calendar entries and invoices with customer addresses.
• Odometer readings on oil-change and repair receipts. Two readings a year apart give you total miles, which the log has to fit inside.

The Clearpath portal walks you through each of these and produces a dated log with the evidence listed. It also checks the total against your odometer — a "business use" percentage over 90% is a red flag we'd rather catch than the IRS.

Standard rate or actual expenses?

You choose per vehicle. If you own the car, you must pick the standard rate in the first year it's used for business to keep the option later; you can switch to actual expenses in a later year but not back. Actual expenses (fuel, insurance, repairs, depreciation, all multiplied by business-use percentage) sometimes win for expensive or heavily used vehicles, but they require receipts for everything and the same mileage proof. For most drivers, the standard rate wins on both dollars and paperwork.

Going forward

Use a mileage app. Stride is free; MileIQ and Everlance are a few dollars a month. Any of them turns next year's log from a reconstruction project into a PDF you upload.

This is general information, not advice for your specific return. Rates and rules change every year.