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How to Track Business Mileage for Tax Deductions

Published on April 15, 2026

One of the easiest tax deductions to claim is also one of the most commonly overlooked: business mileage. Whether you drive for client meetings, supply runs, or delivering products, those miles can add up to real tax savings. The catch? The IRS wants proof. Let me walk you through how to track mileage properly so you never leave money on the table.

Why Mileage Tracking Matters

Many small business owners throw away thousands in potential tax deductions simply because they didn't document their driving. The IRS knows that business mileage is deductible, but they also know it's easy to claim inflated numbers. That's why they require detailed records. If you don't have documentation and the IRS audits you, you'll lose the entire deduction, not just the questionable portion.

Beyond avoiding trouble with the IRS, tracking mileage helps you understand your actual business costs. You might be surprised how much you're spending on gas and wear and tear when you add it up over a year.

Standard Mileage Rate vs. Actual Expenses

The IRS offers two methods for claiming business mileage. The standard mileage method is simpler and works best for most small business owners. You multiply your total business miles by the IRS standard mileage rate (this rate changes annually, so verify the current amount on IRS.gov before calculating your deduction). No receipts needed for gas, just your mileage log.

The actual expense method is more complex. You track every gas purchase, maintenance cost, depreciation, insurance, and registration fee, then calculate the percentage that applies to business use. This only makes sense if you have significant business miles and detailed records. For most owners, standard mileage is simpler and often yields the same or better deduction.

What Counts as Business Mileage

Not all driving counts. Commuting from your home to your office doesn't qualify, even if you stop to pick up office supplies. However, driving from your office to a client site counts. If you have a dedicated home office that qualifies for the home office deduction, trips from that office to client locations or business destinations count as business mileage. However, standard commuting rules are complex, so check with your CPA about what qualifies in your situation.

Here are miles that DO count:

• Driving to client meetings or appointments
• Traveling to or between job sites
• Running to the bank to deposit checks
• Shopping for business supplies or inventory
• Attending industry conferences or professional development
• Traveling for business purposes (as long as it's not your regular commute)

Miles that don't count include your regular commute from home to your main office or workspace, and personal errands.

Best Practices for Logging Trips

You need four pieces of information for each trip: the date, the miles driven, the business purpose, and where you went. You don't need to be elaborate. A simple notebook entry like "March 15, 47 miles, client meeting with ABC Company, downtown to their office and back" is perfect. The IRS just needs to see you're tracking it consistently.

Log your miles when you drive, not weeks later. Your memory will be fresher, and you'll catch trips you'd otherwise forget. If you drive several times a day, you can write it all down in the evening. The key is doing it regularly and soon after the trip.

Keep your mileage log in your car. A small notebook works fine, or use your phone. Some owners keep a clipboard on the passenger seat and jot down trips immediately after arriving at their destination.

Apps and Tools That Make It Easy

Plenty of apps can automate mileage tracking. Many have GPS that detects when you're driving and prompts you to log the business purpose. This removes the guesswork and creates a permanent digital record. These apps back up your data to the cloud, so you won't lose your records if your phone gets damaged.

Popular options include mileage tracking apps that integrate with your accounting software, making the deduction easy to add at tax time. Some accountants recommend using an app because the digital timestamp provides extra credibility if you're ever audited.

If you prefer simplicity, a spreadsheet or even a printed log works fine. The format doesn't matter to the IRS, only that your information is clear and consistent.

What the IRS Expects

Your mileage log should show a pattern and consistency. The IRS wants to see that you're tracking mileage throughout the year, not suddenly producing months of records all at once. If you claim you drove 20,000 business miles but only have documentation for 12,000, the entire deduction can be denied.

The IRS requires contemporaneous records under Section 274(d). A log made at or near the time of the trip is required, not merely recommended. Reconstructed logs are generally not accepted by the IRS in an audit. So the notebook, app, or spreadsheet you keep throughout the year is far more valuable than trying to recreate it in December.

Your mileage log itself is the primary requirement under IRS rules. Supporting evidence like calendar entries showing client meetings, invoices, or receipts from your destination can strengthen your records, but they do not replace the contemporaneous written log.

Getting Started This Week

If you haven't been tracking mileage, start today. Choose your method (app or notebook), pick up where you are now, and be diligent going forward. You can't claim past years you didn't track, but you can capture every mile from this point on. By year-end, you'll have solid documentation of miles that will save you money on your tax return.

If you work with a CPA or bookkeeper, share your mileage log with them before tax season. They can help you decide between standard or actual mileage, combine it with other deductions, and ensure everything is reported correctly.