One extra payment per year saves roughly 4 to 5 years of payments and tens of thousands in interest
The exact savings depend on your loan balance, interest rate, and how far into the loan you are when you start. A borrower with a $300,000 loan at 6% interest, 25 years into a 30-year mortgage, who makes one extra $1,432 payment, will pay off the loan about 4 years early and save approximately $35,000 in interest. A borrower early in the loan with the same balance and rate who makes one extra payment will save closer to 5 years and $60,000 in interest. The earlier you start, the more you save—because extra payments reduce the principal balance that interest accrues against for the remaining years.
The savings are real but not automatic. The extra payment must go toward principal, not toward your next month's regular payment. Some lenders will apply an extra payment to your next scheduled payment instead of reducing principal immediately. Before you send money, contact your lender and confirm they will credit it as a principal reduction in the month you send it.
Key Takeaways
- One extra mortgage payment per year typically shortens a 30-year loan by 4 to 5 years and saves $35,000 to $60,000 in interest, depending on your rate and loan balance.
- The savings are larger if you start early in the loan, because the principal reduction compounds over more remaining years.
- You must instruct your lender to apply the extra payment to principal, not to your next regular payment, or the benefit is lost.
- Making extra payments does not lower your monthly payment—it only shortens the total life of the loan.
- If your mortgage has a prepayment penalty, check the terms before sending extra money; some older loans charge a fee for paying off early.
How the math works: principal reduction and compound interest
Every mortgage payment you make includes two parts: interest and principal. Early in the loan, most of your payment goes to interest. Late in the loan, most goes to principal. When you make an extra payment and direct it to principal, you reduce the balance that interest is calculated against for every remaining month.
On a $300,000 loan at 6% over 30 years, the monthly payment is $1,799. Of that first payment, $1,500 goes to interest and $299 to principal. If you send an extra $1,799 payment and it goes to principal, you reduce the balance by $1,799 instead of $299. That $1,500 difference means $1,500 less balance earning interest next month, and the month after that, and for every month remaining on the loan. Over 4 to 5 years, that compounds into tens of thousands of dollars saved.
The savings are largest when you start early because you have the most remaining years for the interest reduction to compound. A single extra payment in year 1 saves more than a single extra payment in year 25, even though the payment amount is the same.
When to make the extra payment: timing and strategy
You can make an extra payment any month, but the timing affects how quickly the benefit shows up. Most borrowers make one extra payment per year, usually around tax refund time or a bonus. Some make a half-payment twice per year. The frequency does not matter as much as consistency—the key is that the money goes to principal and stays there.
If you have a choice between making one large extra payment or spreading smaller amounts across the year, the total interest saved is nearly identical. The advantage of spreading payments is that you reduce the principal balance earlier in the year, so interest accrues on a lower balance for more months. The advantage of one lump sum is simplicity and the psychological satisfaction of a single large payment.
Do not make extra payments if you carry high-interest debt elsewhere—credit cards, personal loans, or car loans. The interest rate on those debts is almost always higher than your mortgage rate, so paying those down first saves more money overall.
Confirming your lender will apply the payment correctly
Before you send an extra payment, call your lender's customer service line and ask three things: (1) Can I make an extra principal payment? (2) How do I send it so it goes to principal and not to next month's regular payment? (3) Will you confirm in writing that it was applied to principal?
Some lenders have a specific process—a separate payment portal, a phone line for extra payments, or a form you must submit. Others will apply any payment over the regular amount to principal automatically. A few older loan servicing systems will hold extra payments in a suspense account for weeks before applying them. Getting the answer in advance prevents your extra payment from sitting in limbo or being misapplied.
After you send the payment, log into your account online or call back in 2 to 3 business days to confirm the principal balance decreased. If it did not, contact the lender immediately and ask where the money went. Do not assume it was applied correctly.
Prepayment penalties and when they block extra payments
Most mortgages issued in the last 15 years have no prepayment penalty. Older loans, particularly those from the 2000s, sometimes include a clause that charges a fee if you pay off the loan early. The penalty is usually 1% to 3% of the loan balance or a flat fee, and it applies only if you pay off the entire loan early—not if you make extra payments while still making regular payments.
Check your loan documents (the promissory note or deed of trust) or call your lender and ask: "Does my loan have a prepayment penalty?" If it does, the penalty typically expires after 3 to 5 years. If your loan is older than that, the penalty has likely already expired. If it has not, you can still make extra payments—the penalty only triggers if you pay off the entire loan in one lump sum before the penalty period ends.
If a prepayment penalty does apply and you want to make extra payments anyway, the math still works in your favor. The interest you save by reducing principal usually exceeds the penalty cost, but run the numbers with your lender before committing.
The difference between extra payments and biweekly payment plans
Some lenders offer biweekly payment plans, where you pay half your monthly payment every two weeks instead of the full payment once a month. Over a year, this results in 26 half-payments, which equals 13 full payments instead of 12. The effect is similar to making one extra payment per year, but the mechanics are different.
With a biweekly plan, you do not have to remember to send extra money—the lender deducts it automatically. However, biweekly plans sometimes come with a setup fee ($300 to $500) and may not be offered by all lenders. If your lender offers it at no cost, it is a convenient way to achieve the same result as making one extra payment yourself. If there is a fee, you can achieve the same savings by making one extra payment per year on your own, which costs nothing.
What extra payments do not do: common misconceptions
Making extra principal payments does not lower your monthly payment. Your regular payment stays the same for the life of the loan (unless you have an adjustable-rate mortgage, which adjusts based on interest rates, not your payments). The extra payment only shortens how many months you will owe the loan. If your goal is to lower your monthly payment, you would need to refinance, which is a separate process with its own costs and benefits.
Extra payments also do not affect your credit score directly. Paying down principal faster is good financial behavior, but credit bureaus do not reward it. Your credit score is based on payment history, credit utilization, and age of accounts—not on how quickly you pay off a loan.
Finally, extra payments do not create a credit toward future months. If you send an extra $1,000 one month, you still owe your full regular payment the next month. The extra money reduces your total loan balance, not your upcoming obligations.
Frequently Asked Questions
Can I make extra payments if I have a variable-rate mortgage?
Yes. Extra principal payments work the same way on adjustable-rate mortgages as on fixed-rate loans. The interest rate may change, but the principal reduction from your extra payment is permanent. Making extra payments early, before rates rise, is especially valuable because you lock in the principal reduction at the current rate.
What if I can only afford an extra payment every few years?
Any extra principal payment saves interest, even if it is infrequent. A single $5,000 extra payment in year 5 will still reduce your total interest and shorten your loan, though not as much as spreading payments across multiple years. Start with what you can afford.
Should I make extra payments or invest the money instead?
If you can earn a higher return on investment than your mortgage interest rate, investing may build more wealth. If your mortgage is 6% and you can reliably earn 8% or more in the stock market, investing wins mathematically. If you are uncertain about investment returns or prefer the may provide return of paying down debt, extra mortgage payments are a safe choice.
Do extra payments help if I plan to sell the house in a few years?
Extra payments reduce your loan balance, so you will owe less when you sell and keep more of the sale proceeds. However, if you are selling within 2 to 3 years, the interest savings are small. The real benefit of extra payments appears over 5+ years.
Can I reverse an extra payment if I need the money back?
No. Once an extra payment is applied to principal, it is permanent. You cannot withdraw it or treat it as a credit. If you might need the money, do not send it as an extra mortgage payment—keep it in savings instead.