What to Hand Your Tax Preparer About Mileage

A good tax preparer needs five pieces of information from you about your mileage. Bring all five and the appointment goes faster, the deduction is more accurate, and you reduce your audit risk.

1. Total business miles

The single annual number for each vehicle. From your contemporaneous log. If you tracked properly, an app gives you this in one tap.

2. Total miles driven (year)

January 1 odometer reading minus December 31 odometer reading. This is the denominator for business-use percentage. The IRS expects to see it on Schedule C Part IV.

3. Vehicle details

• Make and model
• Year
• Date placed in service for business
• Whether you used it for business in prior years

4. Standard rate or actual expenses?

If standard mileage rate: just provide miles. If actual expenses: provide all year's vehicle costs (gas, insurance, registration, repairs, lease/depreciation). The preparer applies your business-use percentage to actual costs.

5. The log itself

The full log with date, destination, business purpose, miles for every business trip. The preparer does not need to enter every row, but having the log available means they can defend the number if questioned. Bring a CSV or PDF export.

What a preparer will ask if you do not bring the log

A diligent preparer will ask whether you have a contemporaneous log to back the number. If you do not, expect them to either (a) recommend a smaller, defensible deduction figure, (b) require you to sign a statement acknowledging audit risk, or (c) decline to claim the deduction at all. None of these are good outcomes.

What format your preparer wants

• CSV is universal. Most tax software imports CSV.
• PDF is fine for visual review. Less easy to import.
• Spreadsheet (Excel, Google Sheets) works.
• Paper logbook is acceptable but slowest to review.

If the preparer is your accountant year-round

Send mileage updates quarterly so your accountant can build accurate estimated tax payments. A surprise October report of 30,000 untracked miles creates Q4 estimate panic.

What preparers love about app-tracked logs

Auto-tracked logs are by-construction contemporaneous, totals tie to odometer readings, and CSV export is one tap. Preparers spend less time on data entry and more time on actual tax planning. Many recommend specific tracker apps to clients for this reason.

Hand your tax preparer a clean export. Start free with TruMile →