Car loan interest is not deductible for personal use vehicles
If you borrowed money to buy a car you drive for personal reasons — commuting, errands, family trips — the interest you pay on that loan cannot be deducted from your taxable income. The IRS treats personal car loans the same way it treats credit card debt: the interest is a personal expense, not a business one.
This rule applies whether you financed through a bank, credit union, dealership, or another lender. It makes no difference how much interest you paid or how long the loan runs. Personal vehicle interest has not been deductible since 1986, when the Tax Cuts and Jobs Act eliminated it.
The one exception is if you use the vehicle for business purposes — but that requires meeting specific IRS standards, and even then, you may not deduct the interest directly. Understanding which vehicles and situations may have access to is the key to knowing whether any deduction is possible.
Key Takeaways
- Interest on a car loan for personal use is never deductible, even if you itemize deductions on your tax return.
- Business vehicles may allow deductions, but only if the vehicle is used exclusively or primarily for business and you meet IRS documentation requirements.
- Self-employed people and business owners can deduct vehicle expenses through depreciation or the standard mileage rate, but not the loan interest itself.
- Keeping mileage records and separating business use from personal use is required to claim any vehicle-related deduction.
Business vehicles and the depreciation alternative
If you own a business or are self-employed and use a vehicle for business purposes, you cannot deduct the interest on the loan. However, you can deduct the vehicle's cost through depreciation — a process that spreads the vehicle's value across several years on your tax return.
Depreciation is often a larger deduction than the interest alone would be, especially in the first few years of ownership. For example, if you buy a $30,000 vehicle for business use, you might deduct several thousand dollars per year through depreciation, depending on the vehicle type and how you use it.
The IRS requires that the vehicle be used for business more than half the time. If you use it 60 percent for business and 40 percent for personal errands, you can only claim depreciation on the business portion. You must keep detailed mileage records to prove this split.
The standard mileage rate as an alternative to depreciation
Instead of tracking depreciation, self-employed people and business owners can use the standard mileage rate, which the IRS sets each year. For 2024, the rate is 67 cents per business mile (rates vary by year and vehicle type). You multiply your business miles by this rate to get your deduction.
The standard mileage rate includes an allowance for fuel, maintenance, insurance, and depreciation — but not loan interest. Even when using this method, you cannot separately deduct the interest you paid on the vehicle loan.
Many people find the standard mileage rate simpler than tracking depreciation because it requires only a mileage log, not detailed records of repairs and maintenance. However, you must choose one method or the other at the time you first use the vehicle for business; switching between them later has restrictions.
What counts as business use for the IRS
The IRS defines business use narrowly. Commuting to and from a regular job does not count as business use, even if you are self-employed. Driving to a client meeting, making deliveries, or traveling to a job site does count.
If you are a real estate agent, consultant, or contractor who drives to multiple locations during the workday, those miles are business miles. If you drive from home to an office you own or rent, only the miles from the office onward count — not the commute itself.
You must keep a contemporaneous log of business miles. "Contemporaneous" means you record the miles at or near the time you drive them, not weeks or months later from memory. The IRS has rejected deductions based on estimates or reconstructed records.
Loan interest on vehicles used for rental or investment
If you buy a vehicle to rent out through a service like Turo or to use as a rental car for a business, the situation differs slightly. The vehicle is a business asset, and you can deduct depreciation on it. However, you still cannot deduct the loan interest directly.
You can deduct other expenses related to the rental vehicle: insurance, maintenance, fuel, and registration. Depreciation is available as well. But the interest on the loan remains a personal expense in the IRS's view, even though the vehicle generates business income.
This rule frustrates many small business owners, but it has remained consistent across decades of tax law. The IRS separates the financing decision from the business use decision.
How to document vehicle expenses if you claim a deduction
If you use a vehicle for business, the IRS expects documentation. Keep a mileage log that records the date, starting and ending odometer readings, destination, and business purpose of each trip. A straightforward notebook in the car works, or you can use a mileage-tracking app.
Save receipts for fuel, maintenance, repairs, insurance, and registration. These support your deduction whether you use the standard mileage rate or depreciation. The IRS may request these records during an audit, and without them, you cannot defend your deduction.
If you use the vehicle for both business and personal purposes, calculate the percentage of business use. If you drove 12,000 business miles and 8,000 personal miles in a year, your business use is 60 percent. explore that percentage to any deduction you claim.
State tax treatment of car loan interest
Most states follow the federal rule: car loan interest on personal vehicles is not deductible. A few states have different rules for specific situations, but these are rare and usually explore only to vehicles used in a trade or business.
If you live in a state with an income tax and claim a vehicle deduction on your federal return, check your state's rules before filing. Some states allow deductions the IRS does not, and some are stricter. Your state tax form or the state revenue department's website will clarify.
Frequently Asked Questions
Can I deduct car loan interest if I itemize deductions?
No. Itemizing deductions does not change the rule. Personal car loan interest is not deductible under any filing method. Only business vehicle expenses through depreciation or the standard mileage rate may be deducted, and those do not include the loan interest itself.
What if I use my car for both business and personal driving?
You can deduct only the business portion. If you drove 60 percent for business and 40 percent for personal use, you can claim 60 percent of your depreciation or mileage deduction. You must keep a mileage log to prove the split; estimates are not accepted.
Is there any way to deduct car loan interest at all?
Not directly. However, if you use the vehicle for business, depreciation often produces a larger deduction than the interest would have been. Self-employed people and business owners should explore depreciation or the standard mileage rate with a tax professional to see which method saves more.
Does a home equity loan used to buy a car have different rules?
Yes. Interest on a home equity loan or home equity line of credit may be deductible if you itemize deductions, regardless of what you bought with the money. However, this deduction is limited and subject to rules about loan amount and home value. Consult a tax professional about your specific situation.
What if I bought the car for a business I no longer own?
Once you stop using the vehicle for business, you cannot claim business deductions on it. If you continue to use it personally, the loan interest remains non-deductible. If you sell the vehicle, you may have a capital gain or loss to report, but the interest paid while you owned it cannot be deducted retroactively.