What Is the Business Mileage Deduction?

The business mileage deduction allows an eligible taxpayer to deduct the business portion of vehicle costs for qualifying travel. It is most commonly claimed by self-employed people and business owners. The amount is generally calculated with either the standard mileage rate or the actual vehicle expense method—not both for the same vehicle and period.

Which trips may qualify as business mileage?

Qualifying trips must have a real business purpose. Common examples include driving from an office to a client meeting, between job sites, to a bank or supply store for the business, or to a temporary work location when the tax rules allow it.

The starting point matters. A trip from home to a regular office is usually commuting even if the driver takes business calls or carries work materials. If a taxpayer's home qualifies as the principal place of business, travel from that home office to another work location in the same trade or business may qualify. Travel between two separate businesses can also require allocation.

Personal detours do not become business mileage merely because they occur during a business day. The taxpayer should record the destination and business purpose, not simply mark an entire day as business use.

How is the deduction calculated?

There are two principal methods:

1. Standard mileage rate: Multiply qualifying business miles by the IRS rate that applies when the miles were driven. The rate incorporates operating and ownership costs, including a depreciation component.
2. Actual vehicle expense method: Total eligible costs—such as fuel, insurance, repairs, registration, lease payments or depreciation—and multiply mixed-use costs by the business-use percentage.

Business-related parking fees and tolls may generally be deducted separately under the standard-mileage method. Parking at a regular workplace and commuting tolls remain personal.

Eligibility and future flexibility matter. An owner generally must choose the standard mileage method in the first year the vehicle is available for business use to preserve the option of switching methods later. A taxpayer who uses the standard mileage rate for a leased vehicle generally must continue using it for the entire lease period, including renewals.

Business mileage deduction example

Assume a taxpayer drives 20,000 total miles in 2026 and documents 8,000 business miles: 3,000 in the first half of the year and 5,000 in the second half.

If eligible actual costs total $14,000, the 40% business-use percentage produces a preliminary actual-expense amount of $5,600. This comparison is simplified. Depreciation rules, interest, parking, tolls, reimbursements, basis, and method restrictions may change the result.

Where is the deduction reported?

A sole proprietor generally reports car and truck expenses on Schedule C. Schedule C also asks for vehicle-use information, including business, commuting, and other miles. Partners, farmers, rental owners, and the limited categories of employees who may deduct vehicle expenses can use different forms or schedules.

Most employees cannot claim an itemized federal deduction for unreimbursed employee vehicle expenses under current law. An accountable-plan reimbursement from an employer is a different arrangement: the employer reimburses substantiated business costs, and properly handled payments generally are not taxable wages.

Federal and California treatment

Federal law generally permits either calculation method when the taxpayer and vehicle qualify. California FTB Publication 984 similarly describes actual expenses and the standard mileage rate and requires adequate records.

Federal and California depreciation rules do not always match. A taxpayer using actual expenses may need a California adjustment when federal depreciation, bonus depreciation, or Section 179 treatment differs. Review the current Schedule CA instructions instead of assuming the federal amount automatically carries over.

Common mistakes

• Treating commuting as business travel
• Estimating miles after year-end without reliable supporting evidence
• Deducting both the standard mileage amount and fuel, repairs, insurance, or depreciation
• Using one rate for all of 2026 despite the July 1 rate change
• Counting reimbursed expenses again
• Failing to track total, commuting, personal, and business mileage
• Ignoring method-election and leased-vehicle rules

Frequently asked questions

Related terms

• Standard Mileage Rate
• Actual Vehicle Expense Method
• Business Use Percentage
• Business Expense
• Schedule C
• Home Office Deduction

Official sources

• IRS — Topic No. 510, Business Use of Car
• IRS — Publication 463, Travel, Gift, and Car Expenses
• IRS — Standard mileage rates
• California FTB — Publication 984, Business Expenses

The definitions and examples on this page are for informational purposes only and do not constitute tax advice. Tax laws change frequently and individual circumstances vary. Consult a qualified tax professional before making decisions based on this content.