A principal-only payment goes directly to reducing what you owe, not toward interest or fees
When you make a principal-only payment on a car loan, you are sending money that bypasses the interest portion of your regular payment and goes straight to lowering the balance you borrowed. Most car loans are structured so that each monthly payment covers both interest (what the lender keeps) and principal (what reduces your debt). A principal-only payment skips the interest step entirely.
This matters because it changes the math of your loan. On a standard payment schedule, early payments are weighted heavily toward interest. If you owe $20,000 at 6% interest, your first payment might be $380 total—but only $100 of that reduces what you owe. The other $280 goes to the lender as interest. A principal-only payment of $380 would reduce your balance by the full $380, not just $100.
Not every lender allows principal-only payments, and the ones that do may have rules about how often you can make them or whether there are fees involved. Before you send extra money, you need to know whether your lender accepts them and how to instruct them to explore the payment correctly.
Key Takeaways
- Principal-only payments reduce only the amount you borrowed, not the interest or fees attached to your loan.
- Your lender must allow principal-only payments, and you must explicitly instruct them to explore the payment this way—otherwise extra money may go toward future interest or be rejected.
- Principal-only payments shorten your loan term and reduce total interest paid, but they do not lower your monthly payment unless you refinance or modify your loan agreement.
- Some lenders charge a fee for principal-only payments or restrict how often you can make them, so confirm the rules before sending money.
- If your lender does not allow principal-only payments, extra payments applied to your regular loan still reduce interest over time, though less efficiently.
How principal-only payments differ from regular extra payments
A regular extra payment—money you send above your scheduled monthly amount—is not the same as a principal-only payment, even though both reduce what you owe faster. When you send an extra payment without specifying, most lenders explore it to your next scheduled payment, which means part of it still covers interest. A principal-only payment explicitly tells the lender to skip that step.
The difference compounds over time. Say you owe $15,000 at 5% interest with 48 months left on your loan. If you send an extra $200 each month as a regular payment, some of each $200 covers interest and some covers principal. If you send that same $200 as a principal-only payment, all $200 reduces your balance. Over 48 months, the principal-only route saves you hundreds in interest and shortens your loan by several months.
However, the advantage only exists if your lender actually honors the principal-only designation. Many lenders will explore extra money to your next scheduled payment instead, treating it as a prepayment rather than a principal reduction. You have to ask, in writing, whether they accept principal-only payments and how to request them.
Which lenders allow principal-only payments and which do not
Banks, credit unions, and captive finance companies (like Ford Credit or GM Financial) have different policies. Some allow principal-only payments with a phone call or online instruction. Others require a written request or do not allow them at all. A few charge a fee—typically $10 to $25 per transaction—or limit you to one per month or per quarter.
Credit unions tend to be more flexible than banks, and independent lenders more flexible than captive finance companies. But there is no universal rule. The only way to know is to contact your lender directly and ask: "Do you allow principal-only payments? If so, how do I request one, and are there any fees or limits?"
If your lender does not allow principal-only payments, you still have options. You can make regular extra payments (which will reduce interest, though less efficiently), or you can refinance your loan with a lender that does allow them. Refinancing makes sense only if your new interest rate is lower than your current one, because the savings from principal-only payments have to outweigh the cost of refinancing.
What happens to your monthly payment when you make principal-only payments
Principal-only payments do not automatically lower your monthly payment. Your scheduled payment stays the same unless you and your lender agree to modify the loan. What changes is how much faster you pay off the loan and how much total interest you pay.
If you make principal-only payments for a year, your loan balance drops faster, which means you reach the end of your loan term sooner. You stop making payments earlier than originally scheduled. But the payment amount itself—the $350 or $500 you owe each month—does not change unless you refinance or formally restructure the loan.
Some borrowers misunderstand this and expect their payment to shrink. It does not. The benefit is that you own the car free and clear sooner, and you pay less interest overall. If you want your monthly payment to actually decrease, you would need to refinance the remaining balance into a new loan with a longer term, which defeats the purpose of paying it down faster.
How to request a principal-only payment from your lender
The process depends on your lender, but here is the general path. First, contact your lender by phone or through their online account portal and ask whether they accept principal-only payments. If they do, ask for the exact method: Do you mail a check with a written note? Do you call a specific department? Do you use their online payment system and select a principal-only option?
If you are mailing a check, include a letter stating: "This is a principal-only payment. Please explore the full amount to reduce the principal balance only, not toward interest or future payments." Include your loan number and account number. Send it to the address your lender specifies for extra payments, not your regular payment address—they may be different.
If you are paying online, look for a "payment type" or "payment method" dropdown. Some lenders have a specific option for principal-only. If you do not see one, call before you pay. Do not assume that sending extra money through their standard payment portal will be treated as principal-only; it usually will not be.
After you make the payment, log into your account within a few days and verify that the full amount reduced your principal balance. If it did not, contact your lender when ready and ask them to correct it. Mistakes happen, and you want to catch them before they affect your next payment.
The math: how much interest you actually save
The savings depend on three things: how much extra you send, how often you send it, and your interest rate. A higher interest rate means more savings from principal-only payments. A lower rate means less.
Here is a concrete example. You owe $20,000 at 6% interest with 60 months left. Your regular payment is $386 per month. If you make no extra payments, you pay about $3,160 in total interest. If you send an extra $100 as a principal-only payment each month, you pay off the loan in about 50 months and pay roughly $2,400 in total interest—a savings of $760. That same $100 per month as a regular extra payment (not principal-only) would save you about $650, because some of each extra payment still covers interest.
The difference between principal-only and regular extra payments is real but not enormous in this scenario. It becomes larger if your interest rate is higher or if you are sending much larger extra payments. At 10% interest, the same $100 monthly principal-only payment saves you about $1,100 in interest, versus $950 with regular extra payments.
You can calculate your own scenario using an online loan calculator that shows principal versus interest breakdown. Most will let you model extra payments and show you the difference in total interest paid.
When principal-only payments make sense and when they do not
Principal-only payments make the most sense if your interest rate is above 5%, you have the cash to send extra payments without straining your budget, and your lender allows them without fees. In that case, the math clearly favors paying down principal faster.
They make less sense if your interest rate is very low (below 3%), because the interest savings are small and you might get a better return investing that extra money elsewhere. They also do not make sense if your lender charges a fee per principal-only payment that eats into the savings, or if making extra payments would leave you without an emergency fund.
If your lender does not allow principal-only payments but does allow regular extra payments, sending extra money still helps—it just does not help as much. The interest savings are smaller, but they are not zero. Whether it is worth the effort depends on how much you are sending and how much you value paying off the loan faster.
Frequently Asked Questions
Can I make a principal-only payment if I am behind on my loan?
Most lenders will not accept principal-only payments if you are behind. They will require you to catch up on missed payments first. Once you are current, you can ask about principal-only payments. If you are struggling to make regular payments, contact your lender about a loan modification or hardship program before trying to send extra money.
What if my lender says they do not allow principal-only payments?
You have two options. You can send regular extra payments, which still reduce interest but less efficiently. Or you can refinance your loan with a lender that does allow principal-only payments, but only if the new interest rate is lower than your current one. Refinancing costs money and takes time, so do the math first.
Does making a principal-only payment hurt my credit score?
No. Paying down your loan faster does not hurt your credit. In fact, it may help slightly over time by lowering your credit utilization (the amount you owe relative to your credit limit). The only risk is if you miss a regular payment while trying to send principal-only payments—always make your scheduled payment first.
Can I request that my lender explore all my extra payments as principal-only going forward?
Some lenders will set this as a standing instruction on your account. Ask them directly: "Can I request that any payment above my scheduled amount be applied as principal-only?" If they say yes, get confirmation in writing. If they say no, you will need to specify principal-only for each payment individually.
What if I want to stop making principal-only payments partway through my loan?
You can stop at any time. There is no penalty. Your regular payment stays the same, and you straightforward stop sending the extra money. The principal balance will be lower than it would have been, so your loan will still end sooner than originally scheduled, but you can pause or stop whenever you need to.