If you have a dedicated vehicle that you only use for work purposes, you can write off 100% of your mileage on your tax return. If you have a personal vehicle that you sometimes use for your business, you can write off only the miles driven while you work.

For the 2026 tax year, the IRS standard mileage rate is the primary method for determining how many miles you can write off, and there is no upper limit on the number of miles you can claim, provided they are all for legitimate business purposes. As of early 2026, the business mileage rate is approximately 68 to 70 cents per mile. You can write off every single mile driven for business travel, such as visiting clients, picking up supplies, or traveling between two work locations. However, you cannot write off "commuting" miles from your home to your primary office. To survive an audit, you must maintain a meticulous contemporaneous log that includes the date, mileage, destination, and business purpose for every trip. If you are self-employed or a gig-economy worker (like an Uber or DoorDash driver), this write-off is one of your most significant tax deductions, as it accounts for fuel, insurance, and vehicle depreciation. For 2026, digital mileage-tracking apps are the "gold standard" for ensuring your records meet the strict IRS documentation requirements for these unlimited deductions.