How to Make One Extra Mortgage Payment a Year (and Why It Matters)

One extra mortgage payment per year. That's it. No refinancing, no dramatic lifestyle changes, no complicated financial maneuver. Just one additional payment applied to principal — and over the life of a 30-year mortgage, it typically cuts 4–5 years off the loan and saves $20,000–$50,000 in interest depending on your loan size and rate.

Use the Loan Payoff Calculator to run the exact numbers for your mortgage. This article explains why this strategy works, the different ways to execute it, and which approach makes the most sense depending on how you manage money.

Why One Extra Payment Has Such a Big Effect

The key is how mortgage amortization works. On a standard 30-year mortgage, early payments are heavily weighted toward interest. If you have a $350,000 mortgage at 6.5%, your monthly payment is around $2,213. In month one, roughly $1,896 of that goes to interest and only $317 reduces your principal balance.

An extra payment applied to principal skips that interest-heavy ratio entirely. Every dollar reduces the balance directly, which means less interest accrues in every subsequent month. That slightly lower balance in month two means a slightly larger share of month two's regular payment goes to principal. And so on, for the remaining life of the loan.

This compounding effect is why an extra payment early in the loan does considerably more than the same payment late. An extra $2,213 in year one saves more interest than an extra $2,213 in year 25 — because the year-one payment reduces the balance for 29 more years of compounding interest.

How Much Does One Extra Payment Actually Save?

Here are the savings from making exactly one extra payment per year on different loan amounts at 6.5% interest, 30-year term:

The proportions stay roughly consistent because amortization math scales linearly with loan size. The savings as a percentage of the loan and the years saved are similar across all balances — what changes is the absolute dollar amount saved.

At higher interest rates, the savings are larger. At a 7.5% rate, one extra payment per year on a $300,000 mortgage saves closer to $50,000 and cuts about 5 years. At 5%, the savings drop to around $25,000 and about 4 years — because there's less interest to eliminate.

Run your specific numbers in the Loan Payoff Calculator using your actual balance, rate, and remaining term.

Four Ways to Make One Extra Payment a Year

Method 1: Bi-Weekly Payments

This is the most automated approach. Instead of making one full payment per month, you pay half your monthly payment every two weeks. Over a year, that adds up to 26 half-payments — the equivalent of 13 full monthly payments instead of 12.

The math: 52 weeks ÷ 2 = 26 bi-weekly payments × 50% of monthly payment = 13 full payments.

The extra payment happens naturally because some months have three bi-weekly payment dates instead of two. You don't have to think about it or plan around it.

Important caveat: Not every lender correctly processes bi-weekly payments. Some hold the first payment until the second arrives and then apply both as a regular monthly payment — which completely defeats the purpose. Before setting this up, call your servicer and confirm they apply each payment immediately to principal as received. If they don't, use one of the other methods below.

Method 2: Divide by 12, Add to Each Payment

Take your regular monthly payment and divide by 12. Add that amount to every monthly payment, labeled as extra principal.

Example: Monthly payment of $1,896. $1,896 ÷ 12 = $158. Pay $2,054 every month, with $158 designated as additional principal.

Over 12 months, you've paid one extra payment's worth of principal without ever writing a single large check. This method smooths the extra cost evenly across all 12 months, which makes it easier to budget.

The key: make sure your lender applies the overage to principal, not to the next month's payment. Most lenders have an online payment option to designate extra amounts as principal prepayment. If you're mailing a check, write "principal only" in the memo line and send a separate note — though electronic payment systems are more reliable.

Method 3: One Lump Sum in January (or Any Month)

Make your regular monthly payment every month, then make one full extra payment in a single month — typically in January from a year-end bonus, tax refund (average US tax refund is around $3,100), or other windfall.

This is the simplest approach if you receive irregular income. One payment, once a year, clearly labeled as principal prepayment.

The timing matters a little but not dramatically. A January extra payment saves slightly more than a December extra payment because it reduces the balance for one more month. But the difference across a full year is small — if the money is available in October, making the payment in October rather than waiting until January is better than the alternative of not making it at all.

Method 4: Budget One Month as a "Double Payment" Month

Choose one month each year — often February (the shortest month, so budgets sometimes have slack) or a month with a third paycheck if you're paid bi-weekly — and pay double.

This is essentially the same as Method 3 but pre-scheduled rather than event-dependent. If you get paid bi-weekly, there are two months per year with three paycheck dates. Many people find it natural to use those months to make an extra debt payment.

Making Sure the Extra Payment Actually Goes to Principal

This is the step most people skip and the one that matters most.

If you send extra money and it's applied to your next month's payment rather than to principal, you haven't prepaid anything — you've just paid ahead. The interest keeps accruing on the full balance. The loan doesn't get shorter.

When making extra principal payments:

• Use your lender's online portal and look for a "principal only" or "additional principal" option in the payment breakdown
• If paying by check, write "principal prepayment" in the memo and attach a note
• After the payment posts, verify your statement shows the full extra amount applied to principal and that your next payment due date didn't simply move forward
• If your servicer applies it incorrectly, call and request a correction before the end of the month

Some lenders make this easier than others. If yours makes it consistently difficult, consider automating the bi-weekly payment method through your bank's bill pay system instead of through the servicer.

Is One Extra Payment Worth It Compared to Investing the Money?

This is the right question to ask, and the honest answer depends on your mortgage rate.

If your mortgage rate is 6–7% or higher, the guaranteed return on paying down the principal is competitive with historical stock market returns after tax — and it's risk-free. At those rates, the extra payment is a reasonable choice even from a pure math standpoint.

If your mortgage rate is 3–4% (common for loans originated in 2020–2021), the math tilts toward investing. A diversified stock index has historically returned 7–10% annually over long periods. Paying down a 3% mortgage to earn a guaranteed 3% when you could potentially earn 7% investing involves a real opportunity cost.

The psychological value of debt reduction is real and shouldn't be dismissed — but it's worth running both scenarios. The Loan Payoff Calculator shows exactly how much interest you'd save with extra payments. Compare that to what those same dollars might grow to over the same period at a reasonable investment return, then decide based on your rate, risk tolerance, and overall financial picture.

For most people with mortgages above 5.5–6%, one extra payment a year is a straightforward, low-effort win. For those with sub-4% rates, that money likely works harder in a tax-advantaged investment account.

One Extra Payment vs. Refinancing

Refinancing to a lower rate or shorter term often produces larger savings than extra payments alone — but it comes with upfront costs (typically $3,000–$7,000 in closing costs) and only makes sense if the rate drop is meaningful and you plan to stay in the home long enough to break even.

Extra payments require no closing costs, no paperwork, no lender approval. They work on any existing mortgage at any rate. And they're reversible — if your financial situation changes, you can simply stop making the extra payment without penalty.

If you can qualify for a refinance to a significantly lower rate, do that first, then layer in extra payments if you want to accelerate further. One extra payment per year on a $300,000 mortgage at 5% saves around $25,000 over the life of the loan — a meaningful outcome without any of the friction that comes with refinancing.