Car Loan Interest Is Deductible Only If You Use the Car for Business
The short answer: you cannot deduct car loan interest if you use the car for personal driving, commuting to work, or family trips. The IRS does not allow it. However, if you use the car primarily for business purposes—such as running a delivery service, operating as a rideshare driver, or using it for work-related travel that is separate from commuting—you may be able to deduct the interest portion of your loan payments.
The distinction matters because the IRS treats personal car loans and business car loans differently. A personal car loan is considered a consumer loan, and consumer loan interest is never deductible. A business car loan, by contrast, is treated as a business expense, and business expenses can reduce your taxable income.
Even if you do use your car for business, you cannot straightforward deduct all the interest. You can only deduct the interest that corresponds to the percentage of time you use the car for business. If you use your car 60 percent for business and 40 percent for personal use, you can deduct 60 percent of the interest you paid that year.
Key Takeaways
- Personal car loan interest is never deductible, even if you drive to work or use the car occasionally for business errands.
- Business car loan interest may be deductible only if the car is used primarily for business purposes and you can document that business use.
- You deduct only the interest portion of your loan payment, not the principal, and only for the percentage of time the car is used for business.
- You must keep records showing how often you use the car for business versus personal driving, because the IRS may ask for proof.
- Self-employed people and business owners should track mileage or maintain a log to support any deduction they claim.
How the IRS Defines Business Use
The IRS considers a car to be used for business if you drive it to earn income in a trade or business you operate. This includes self-employed people, gig workers, and business owners. It does not include driving to a job where you are an employee, even if your employer does not reimburse your mileage.
Common examples of business use are: operating a taxi or rideshare service, making deliveries, visiting clients or job sites, traveling to meetings for your business, or using the car to transport materials or equipment for work. Driving to your office or workplace as an employee does not count, because that is considered commuting.
If you own a business and use a car partly for business and partly for personal errands, you need to track the split. The IRS expects you to keep a mileage log or similar record that shows business miles versus personal miles. Without documentation, you cannot claim the deduction if you are audited.
Separating Interest from Principal in Your Loan Payments
Your monthly car loan payment includes two parts: interest and principal. Only the interest portion is deductible. Your lender should provide you with a statement each year showing how much interest you paid during that tax year—this is often called a 1098-T or a similar statement, though car loans may not always generate a formal tax document.
If your lender does not provide an interest breakdown, you can calculate it yourself or request it from the lender. Early in the loan, most of your payment goes toward interest. Later in the loan, more goes toward principal. For example, on a five-year loan, you might pay 60 percent interest in year one but only 20 percent interest in year five.
Once you know the total interest paid for the year, multiply that amount by your business-use percentage. If you paid $2,000 in interest and used the car 50 percent for business, your deductible interest is $1,000.
Documentation You Need to Keep
The IRS requires evidence that you actually used the car for business. A mileage log is the strongest form of proof. You should record the date, starting mileage, ending mileage, business purpose, and destination for each business trip. You do not need to log every single trip, but you should log enough trips throughout the year to establish a pattern and support your claimed percentage.
Alternatively, you can keep receipts, invoices, or calendar entries that show business trips. If you are a rideshare driver, your app records may serve as documentation. If you make deliveries, delivery confirmations work. The key is being able to show the IRS that your claimed business use is real and consistent.
Keep your loan statements and interest documentation together with your mileage records. If you are audited, the IRS will want to see both the interest you paid and proof that you used the car for business at the rate you claimed.
Alternative: The Standard Mileage Rate
Instead of tracking actual interest and expenses, many self-employed people and business owners use the standard mileage rate. The IRS sets this rate each year, and it covers fuel, maintenance, depreciation, and interest all in one number. For 2024, the standard mileage rate for business use is 67 cents per mile (this changes annually).
To use the standard mileage rate, you multiply your business miles by the current rate. For example, if you drove 10,000 business miles in a year at 67 cents per mile, your deduction is $6,700. You do not separately deduct the interest; it is included in the rate.
The standard mileage rate is often simpler than tracking actual expenses and interest, especially if you do not want to calculate the business-use percentage of your loan interest. However, you cannot use the standard mileage rate if you have already claimed depreciation on the car using a different method in a previous year. Choose one method and stick with it for the life of the vehicle.
When You Cannot Deduct Car Loan Interest
You cannot deduct car loan interest if the car is used only for personal driving, even if you occasionally drive it for work-related tasks. Commuting to an office job, driving to the grocery store, taking family trips, or using the car for personal errands does not may have access to as business use.
You also cannot deduct interest on a car loan if you are an employee and your employer does not reimburse your mileage. Some employers offer mileage reimbursement programs, but that reimbursement is separate from a tax deduction. If your employer pays you back, you do not need to deduct the expense because you were not out of pocket.
Leasing a car instead of financing it changes the rules slightly. Lease payments are sometimes deductible as a business expense if the car is used for business, but the rules are different from loan interest. If you lease, consult a tax professional about what portion of your lease payment you can deduct.
Frequently Asked Questions
Can I deduct car loan interest if I drive to work?
No. Commuting to your job is considered personal use, not business use, even if you occasionally use the car for work errands. The IRS does not allow deductions for commuting expenses. If you are self-employed and use the car to visit clients or job sites, that is different—that counts as business use.
What if I use my car for both business and personal driving?
You can deduct only the interest that corresponds to your business-use percentage. If you use the car 40 percent for business and 60 percent for personal use, you can deduct 40 percent of the interest you paid. You must keep records showing how you calculated this percentage, such as a mileage log.
Do I need a separate business loan to deduct the interest?
No. The type of loan does not matter—what matters is how you use the car. A personal car loan can have deductible interest if you use the car for business. However, you must document the business use and calculate the business-use percentage accurately.
What if my lender did not send me an interest statement?
Contact your lender and request an interest breakdown for the tax year. Most lenders can provide this information. If you cannot get it from the lender, you can calculate it using your loan documents and payment history, or work with a tax professional to reconstruct the figure.
Is the standard mileage rate better than deducting actual interest?
It depends on your situation. The standard mileage rate is simpler because you do not have to separate interest from principal or track actual expenses. However, if you have a high-interest loan and drive many business miles, deducting actual interest might give you a larger deduction. Compare both methods for your situation, but remember you can only use one method per vehicle per year.