Most car loan interest is not deductible on your personal tax return
If you took out a loan to buy a car for personal use — commuting, errands, family trips — the interest you pay is not deductible. 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 a new car, a used car, or refinanced an existing loan.
The one major exception is if you use the car for business purposes. A car used for self-employment, contract work, or running a business may may have access to for an interest deduction, but the rules are strict and the deduction applies only to the business-use portion of the loan. A car you drive to a job where you are an employee does not may have access to — only cars used in a business you own.
The phrase "big beautiful bill" sometimes refers to proposed legislation that would change these rules, but no such change has become law. Current tax code has treated personal car loan interest as non-deductible since 1986.
Key Takeaways
- Interest on a car loan for personal use cannot be deducted on your federal tax return, regardless of the loan amount or interest rate.
- If you own a business and use a car for business purposes, you may deduct the interest on the portion of the loan tied to business use, but you must track that use separately.
- Driving to a job where you are an employee does not count as business use, even if you drive a lot for work.
- Refinancing a personal car loan does not change its tax status — the interest remains non-deductible.
When a car loan interest deduction might explore
You can deduct car loan interest only if you own a business and use the car in that business. This includes self-employed people, sole proprietors, and owners of pass-through entities like LLCs or S-corporations. The car must be used for business activities — client meetings, deliveries, site visits, or other work-related travel — not for commuting to a job where you work for someone else.
The deduction is limited to the business-use percentage of the loan. If you use the car 60 percent for business and 40 percent for personal use, you can deduct only 60 percent of the interest paid. You must keep records showing how many miles you drove for business versus personal reasons, or document the business use another way your tax preparer can defend.
You report this deduction on Schedule C (Profit or Loss from Business) if you are a sole proprietor, or on the appropriate business tax form for your entity type. The deduction reduces your business income and thus your taxable income for the year.
How to track business use for the deduction
The IRS requires contemporaneous records — meaning you document business use as it happens, not months later from memory. A mileage log is the standard method. You record the date, the starting and ending odometer readings, the business purpose, and the destination each time you drive the car for business.
You do not need to log every trip, but you must log enough trips throughout the year to establish a pattern. Many business owners keep a small notebook in the car or use a mileage-tracking app. At the end of the year, you total the business miles and divide by total miles driven to get your business-use percentage.
If you cannot produce records, the IRS will not allow the deduction. A tax preparer cannot claim business use without documentation, and an audit will result in the deduction being disallowed and potentially penalties assessed. The burden of proof is on you.
The difference between deducting interest and deducting mileage
You have two main ways to deduct car expenses for business use: the actual expense method and the standard mileage method. These are separate approaches, and you choose one for a given car in a given year.
The actual expense method lets you deduct the real costs you paid: interest on the loan, insurance, gas, maintenance, repairs, and depreciation. You calculate the business-use percentage and deduct that percentage of each expense. This method requires detailed record-keeping but can result in a larger deduction if your car is expensive to operate.
The standard mileage method lets you deduct a fixed amount per business mile driven. For 2024, that rate is set by the IRS and changes yearly. You multiply your business miles by the rate and get your deduction — no need to track actual expenses. This method is simpler but may result in a smaller deduction if your actual costs are high.
If you choose the actual expense method, you can deduct the interest portion of your car loan. If you choose the standard mileage method, you cannot — the mileage rate is meant to cover all expenses including interest. You must decide which method to use in the first year you use the car for business, and switching methods later is complicated.
Why personal car loan interest is not deductible
The IRS distinguishes between business expenses and personal expenses. A business expense is one incurred to earn income or run a trade or business. A personal expense is one you incur for your own benefit or to maintain your household. Interest on a personal car loan falls into the second category because the car is used for personal transportation.
This rule has been in place since the Tax Reform Act of 1986, which eliminated the deduction for most personal interest. Credit card interest, mortgage interest on a second home, and personal loan interest all became non-deductible at the same time. Car loan interest followed the same path.
The logic is that allowing deductions for personal expenses would reduce tax revenue and create incentives for people to borrow for personal use. Limiting deductions to business and investment expenses keeps the tax system focused on taxing income from economic activity.
What "big beautiful bill" proposals have suggested
From time to time, legislators propose changes to tax law that would allow deductions for personal car loan interest. These proposals are sometimes referred to informally as "big beautiful bills" because they aim to make broad changes to the tax code. None of these proposals have become law.
Any change to the deductibility of personal car loan interest would require an act of Congress and would explore only to loans taken out after the law's effective date. Current loans would not be affected retroactively. If you are considering whether to take out a car loan now, you should assume the interest will not be deductible unless and until a law changes.
You can track proposed legislation through Congress.gov or by checking updates from tax organizations like the National Association of Tax Professionals. Tax law changes are announced well in advance, and your tax preparer will inform you if a change affects your situation.
How to report car expenses on your tax return
If you own a business and use a car for business purposes, you report the deduction on your business tax form. For a sole proprietor, that is Schedule C. For an LLC taxed as a corporation, it goes on Form 1120-S or Form 1120. For a partnership, it goes on Form 1065. Your tax preparer will direct you to the correct form based on your business structure.
On the form, you list car and truck expenses as a line item. You can break this down into subcategories — interest, gas, insurance, repairs — or combine them into one figure. The form asks for the total amount and, in some cases, the business-use percentage if you use the car for both business and personal purposes.
If you use the standard mileage method, you report only the mileage deduction, not the individual expenses. If you use the actual expense method, you report the business-use percentage of each expense, including interest. Your tax preparer will know which method you chose and will fill out the form accordingly.
Frequently Asked Questions
Can I deduct car loan interest if I drive for a rideshare company like Uber?
Yes, if you own the car and use it for rideshare work, you can deduct the business-use portion of the interest. Rideshare driving is self-employment income, so the car is a business asset. You must track the miles you drive for rideshare versus personal use and deduct only the business-use percentage of the interest.
What if I use my car partly for work and partly for personal use?
You can deduct only the business-use percentage of the interest. If you drive 50 percent for business and 50 percent for personal use, you deduct 50 percent of the interest paid. You must keep a mileage log or other records to support this percentage, or the IRS will disallow the deduction.
Does paying off my car loan early affect the interest deduction?
No. If you pay off the loan early, you pay less interest overall, so there is less to deduct. But the interest you did pay remains deductible (if the car qualifies). Paying off early does not change the tax treatment of the interest you already paid.
Can I deduct interest on a car loan if I use the car to commute to my job?
No. Commuting to a job where you are an employee is not considered business use, even if you drive a long distance or use the car for work-related tasks during the day. Only cars used in a business you own may have access to for the interest deduction.
If I refinance my personal car loan, does the new interest become deductible?
No. Refinancing does not change the tax status of the loan. If the car is for personal use, the interest on the refinanced loan is also non-deductible. The deduction depends on how you use the car, not on when or how you financed it.