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Mileage is one of the most valuable deductions for self-employed people and small businesses that drive, and one of the most commonly lost in an audit. The deduction is usually not the problem. The log is. This guide covers what the IRS expects, how to choose between the two deduction methods, the commuting trap, and three ways to keep a log you'll actually maintain.
What the IRS requires in a mileage log
For business use of a vehicle, the IRS (see Publication 463) expects adequate records made at or near the time of the trip. A compliant log records, for each business trip:
- Date
- Destination (where you went)
- Business purpose (why: "client site visit — Smith kitchen remodel," not just "business")
- Miles driven
Plus, for the year: total miles driven in the vehicle (business + personal), usually from odometer readings at the start and end of the year, and business miles total.
"Near the time" matters. A log rebuilt in April from memory is much weaker than one kept week by week. Calendars, invoices and receipts help support it but don't replace it.
Standard mileage rate vs. actual expenses
You generally choose one of two methods per vehicle.
Standard mileage rate: multiply business miles by the IRS rate for the year. For reference, it was 70 cents per mile for 2025; check IRS.gov for the 2026 rate. You can still deduct business parking fees and tolls separately.
Actual expenses: deduct the business-use percentage of gas, oil, repairs, insurance, registration, lease payments or depreciation, and so on. This needs more records.
| Standard rate | Actual expenses | |
|---|---|---|
| Recordkeeping | Mileage log, plus parking/tolls | Mileage log plus all vehicle receipts |
| Usually better for | Efficient cars, high mileage | Expensive vehicles, high operating costs, lower mileage |
| Switching rules | Generally choose it in the first year the vehicle is used for business | Restrictions apply; ask your tax pro |
Many small business owners use the standard rate for simplicity. Run both numbers once with your tax pro in the first year, because that choice can limit your options later.
The commuting trap
Driving from home to your regular workplace is commuting, and it isn't deductible, even if you take calls on the way. Common deductible trips include:
- Between two work locations (office → client site)
- To a temporary work location (for example, a job site for a contractor)
- From a home office that is your principal place of business to other business locations
- To the bank, supplier, or post office for business
The rules have nuances, especially for home offices and temporary vs. regular locations. If most of your miles fall into a gray area, get advice before you claim them.
Three ways to keep the log
1. A GPS mileage app (least effort)
An app records drives automatically or with one tap, and you classify each as business or personal. This is the most reliable way to meet the "at or near the time" standard.
SparkReceipt includes a mileage tracker (GPS or manual) alongside its receipt capture, so mileage and expense receipts live in one place and can flow to QuickBooks Online or Xero. (Features as marketed when we checked; confirm current details on their site.)
2. A spreadsheet (free, needs discipline)
Columns: Date | Start | Destination | Purpose | Odometer start | Odometer end | Miles | Parking/Tolls. Add an annual row for January 1 and December 31 odometer readings. Update it weekly from your calendar.
3. A paper notebook in the car (old-school, works)
Totally acceptable if it's complete and kept as you go. Photograph the pages monthly so a lost notebook doesn't wipe out your deduction.
A weekly 10-minute routine
- Open your log and your calendar side by side.
- Classify every drive from the week (app) or add missing trips (spreadsheet).
- Write a specific business purpose for each.
- Capture parking and toll receipts.
- Once a month, export or back up the log. Keep it with your tax records for the full retention period.
Mistakes that cost people the deduction
- Round-number estimates ("about 1,000 miles a month"). Auditors spot these right away.
- Vague purposes like "meeting" or "errands."
- Claiming 100% business use of the only family car.
- Missing odometer totals for the year.
- Deducting commuting miles.
FAQ
Can I use Google Maps timeline as my log? Location history can help reconstruct trips, but it doesn't record business purpose. Use it as support, not as the log itself.
Do W-2 employees get to deduct mileage? Under current federal law, unreimbursed employee expenses generally aren't deductible for most employees, though some states differ. Employees should ask for reimbursement under an accountable plan.
What about electric vehicles? The standard mileage rate applies the same way. Check the IRS guidance for the year.
How long do I keep mileage logs? As long as the supporting records for that return. At least 3 years in the normal case, and many keep 7.
Not tax advice. Questions: [email protected].
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