How to Track Mileage for Taxes: Log Rules and Deduction Methods

To track mileage for taxes, log five details for every business trip while the trip is fresh: the date, your odometer reading at the start, your odometer reading at the end, where you went, and the business reason for going. The IRS standard mileage rate for 2026 is 72.5 cents per mile,¹ so a full year of driving adds up fast. But the deduction only works if your records can survive scrutiny, and before you start logging anything, you need to know whether you can claim the deduction at all.

Check Whether You Can Deduct Mileage in the First Place

If you’re self-employed, a sole proprietor, a freelancer, or an independent contractor, you can deduct business mileage. If you’re a regular W-2 employee, you almost certainly cannot.

Federal law eliminated the deduction for unreimbursed employee business expenses, including mileage, for regular employees. A salaried worker driving to client sites, hauling equipment, or running errands for an employer gets no federal mileage deduction, even with a perfect log.² The only W-2 employees who can still claim vehicle costs are Armed Forces reservists, qualified performing artists, fee-basis state or local government officials, and employees with impairment-related work expenses.

If your employer already reimburses your mileage under an accountable plan at or below the IRS standard rate, that reimbursement is tax-free and there’s nothing left to deduct. Tracking still helps you get paid, but it’s not a tax exercise.

Know Which Trips Count

Not every work-related drive qualifies, and confusing business travel with commuting is one of the fastest ways to lose a deduction in an audit.

Trips That Qualify

Deductible business mileage covers trips that directly serve your trade or profession. Driving from one work location to another during your day, visiting a client or customer, picking up supplies, or heading to a business meeting all count.³ If you maintain a home office that qualifies as your principal place of business, trips from home to any other work location in the same trade or business are deductible too.⁴

Travel to a temporary work location is also deductible, but only if you realistically expect the assignment to last one year or less. The moment that expectation changes and you anticipate working there beyond a year, every trip going forward becomes nondeductible.⁵

The Commuting Rule

Your daily drive from home to your regular place of business is commuting, and commuting is never deductible. That holds no matter how far you drive, whether you take work calls on the way, or whether you carry tools and materials in your vehicle. The IRS treats it as a personal expense.³ The home-office exception is the main workaround: when your home genuinely serves as your principal business location, there’s no commute to worry about because your workplace is where you live.

What Each Log Entry Must Contain

Section 274(d) of the Internal Revenue Code requires “adequate records” for any deduction involving listed property, which includes vehicles.⁶ IRS Publication 463 spells out what that means in practice. Each entry in your log needs five pieces of information:

The specific calendar date of the trip.
The odometer reading when you left and the reading when you arrived, so the exact mileage is calculable.
The destination — the city, town, or area you traveled to.
The business purpose, described concretely enough to verify. “Met with client about contract renewal” or “picked up printing supplies” works. “Business errands” does not.
The business relationship, if the trip involves meeting someone: who they are and how they connect to your work.

These elements come directly from the IRS’s own substantiation table in Publication 463.⁷ An auditor wants to see enough detail on each entry to confirm the trip genuinely served a business purpose.

The single most important habit is recording trips at or near the time they happen. A log you reconstruct from memory at tax time is far weaker than one filled in daily. The IRS uses the word “contemporaneous” for a reason: entries made the same day as the trip are presumed more reliable, and that presumption matters if your return is examined.

Pick a Tracking Method and Stick With It

A paper logbook kept in your glove compartment works fine. Pre-formatted mileage ledgers are cheap at any office supply store, and the low-tech approach has the advantage of simplicity: write down the numbers, jot a note, move on. The downside is that it’s easy to forget an entry or misplace the book.

Smartphone mileage-tracking apps solve the forgetting problem by using GPS to detect and record trips automatically. Most let you swipe to classify each trip as business or personal, sync data to cloud storage as a backup, and generate year-end reports formatted for tax preparation.

The specific tool matters less than consistency. Pick one method and use it all year. A log that covers January through April and then goes silent is almost as bad as no log at all, because the IRS may disallow the months you didn’t track. Set a recurring reminder if you have to. And record the odometer reading on January 1 and December 31 every year, since your total annual mileage is what you’ll compare business miles against.

Decide Between the Standard Rate and Actual Expenses

Your tracking effort depends partly on which deduction method you use. There are two.

Standard Mileage Rate

For 2026, the IRS rate is 72.5 cents per business mile.¹ The rate covers depreciation, gas, insurance, maintenance, and repairs all rolled together. Multiply your business miles by 0.725. Fifteen thousand business miles works out to a $10,875 deduction.

On top of the standard rate, business-related parking fees and tolls are deductible separately. Parking at your regular place of business doesn’t count, but parking at a client’s office or paying a toll on the way to a job site does.⁸ Keep those receipts.

Actual Expense Method

This approach can produce a larger deduction for expensive vehicles or those with heavy business use, but it takes more bookkeeping. You total every cost of operating the car for the year: gas, oil, tires, repairs, insurance, registration, lease payments, and depreciation.⁹ Then you multiply the total by the percentage of miles driven for business. If your car covered 20,000 total miles and 12,000 were for business, your business-use percentage is 60%, and you deduct 60% of your total costs.⁸ You’ll need receipts for every fuel purchase, repair bill, insurance premium, and registration fee, and depreciation is calculated separately with statutory caps.

Switching Between Methods

If you own the vehicle, you must choose the standard mileage rate in the first year the car is available for business use if you want the option to switch later. After that first year, you can move to actual expenses in any later year. Once you switch to actual expenses, you can return to the standard rate only if you haven’t claimed accelerated depreciation on the vehicle.⁹

For a leased vehicle, the rule is more rigid: if you start with the standard mileage rate, you must use it for the entire lease period, including renewals.⁹ You also can’t use the standard mileage rate if you operate five or more vehicles simultaneously. Fleets have to use actual expenses.

How Long to Keep Records, and What Happens If You Don’t

Keep your mileage logs and supporting receipts for at least three years from the date you filed the return or the return’s due date, whichever is later. That’s the general window the IRS has to audit. If you underreport your gross income by more than 25%, the window stretches to six years.¹⁰ Holding records for six or seven years costs nothing but storage space and removes the guesswork.

If the IRS examines your return and you can’t produce adequate records, the mileage deduction gets disallowed. You then owe the tax you originally avoided, plus interest from the original due date. An accuracy-related penalty of 20% can also be assessed on the underpayment if the IRS finds negligence or a substantial understatement of tax.¹¹ Interest continues to accrue on the penalty. A $3,000 disallowed deduction might only save $700 in tax up front, but the penalty and interest on that $700 can grow quickly over the couple of years it takes to resolve. The log is your insurance against all of it.

1
Internal Revenue Service. IRS Sets 2026 Business Standard Mileage Rate at 72.5 Cents per Mile, Up 2.5 Cents
2
Internal Revenue Service. Instructions for Form 2106 (2025) – General Instructions
3
Internal Revenue Service. Publication 463 (2025), Travel, Gift, and Car Expenses – Section: Transportation
4
Internal Revenue Service. Publication 587 (2025), Business Use of Your Home
5
Internal Revenue Service. Topic No. 511, Business Travel Expenses
6
Office of the Law Revision Counsel. 26 USC 274 – Disallowance of Certain Entertainment, Etc., Expenses
7
Internal Revenue Service. Publication 463 (2025), Travel, Gift, and Car Expenses – Section: Table 5-1
8
Internal Revenue Service. Publication 463 (2025), Travel, Gift, and Car Expenses
9
Internal Revenue Service. Topic No. 510, Business Use of Car
10
Internal Revenue Service. Topic No. 305, Recordkeeping
11
Internal Revenue Service. Accuracy-Related Penalty