IRS Mileage Log Requirements

What the IRS requires in a mileage log

IRS Publication 463, chapter 5, lists the elements you have to prove for car expenses (Table 5-1). Turned into a log, that means these fields:

Odometer readings for every single trip are not required. The trip mileage is. Many people still note start and end odometer readings per trip because it makes the miles easy to prove, and the IRS example log in Publication 463 (Table 5-2, "Daily Business Mileage and Expense Log") has columns for them.

When you have to write it down: "timely kept" records

The IRS asks you to record the details "at or near the time" of the trip. You do not have to write each trip down the same day: Publication 463 says a log kept on a weekly basis that accounts for the week's use counts as a timely kept record.

A log reconstructed months later is weaker evidence. If you missed some trips, you can still support them with your own detailed statement plus other evidence (calendar entries, invoices, delivery records), but that is harder than showing a log. See what to do if you forgot to track mileage.

Sampling is allowed. You can keep an adequate record for part of the year (for example the first week of each month) and use it for the whole year, if you can show the sample periods are representative of your normal use.

Regular routes are simpler. If the business purpose is clear from the circumstances, such as a sales or delivery route, Publication 463 lets you record the route length once and then log the date of each trip and your total miles for the year.

Sample IRS mileage log

This is what a compliant log looks like in practice. The columns follow the IRS example log in Publication 463; the year summary at the bottom is the part people most often forget.

Free IRS mileage log templates

Prefer to fill in a file? Both templates have every column above. The Excel version works out miles from the odometer and applies 72.5¢ or 76¢ by date.

Is there an IRS-approved or IRS-compliant mileage log?

The IRS does not approve or certify mileage logs, apps or templates. Its own example log in Publication 463 is marked "This is not an official Internal Revenue form." When a product calls itself "IRS-approved", it means the log records the elements the IRS asks for, nothing more.

So the test for an "IRS-compliant" log is simple: could someone read it and see, trip by trip, when you drove, where, why, and how far, and could you show your total miles for the year? A paper notebook, a spreadsheet, a GPS app export and a PDF from this generator can all pass that test. An app export with blank purposes or a single annual estimate cannot.

What happens if you don't have a mileage log

Cars are "listed property", so section 274(d) of the tax code requires you to substantiate the expense with adequate records or sufficient evidence. The usual rule that lets a court estimate a deduction does not apply to these expenses. In practice, an examiner can disallow the whole mileage deduction when there is no log.

You would then owe the extra tax plus interest, and the IRS can add a 20% accuracy-related penalty on the underpayment caused by negligence or a substantial understatement. Schedule C even asks directly, in Part IV, whether you have evidence to support the deduction and whether that evidence is written.

If you are missing records for this year, start a proper log today and rebuild the past months from calendars, invoices and map history as carefully as you can.

How long to keep your mileage log

Keep the log and receipts for at least 3 years from the date you file the return that claims the deduction (a return filed early counts as filed on the due date). If you depreciate the car under the actual expense method, keep business-use records for every year of the recovery period.

Standard mileage rate or actual expenses: you need the log either way

With the standard mileage rate you multiply business miles by the IRS rate: for 2026, 72.5¢ for miles driven January 1 to June 30 and 76¢ from July 1. With actual expenses you deduct the business share of gas, insurance, repairs and depreciation, and the business share comes from your log (business miles divided by total miles).

If you want the standard rate for a car you own, choose it in the first year the car is used for business. For a leased car, you must keep using it for the whole lease. See the 2026 rate change and standard rate vs actual expenses.