One extra payment a year cuts years off your mortgage and saves tens of thousands in interest

A single extra mortgage payment each year—usually made by splitting your regular payment into two smaller ones paid every two weeks instead of one monthly payment—shortens a 30-year mortgage by roughly 4 to 6 years. The exact reduction depends on your interest rate, loan balance, and when you start, but the math is direct: every dollar of principal you pay early stops accruing interest for the remaining life of the loan.

On a $300,000 mortgage at 6.5 percent interest, one extra payment per year saves approximately $60,000 to $80,000 in total interest paid over the life of the loan. The savings are smaller on lower-rate mortgages and larger on higher-rate ones. The earlier you start making extra payments, the more you save, because you are reducing the principal balance while interest rates are still being calculated on a larger amount.

The catch is that this strategy only works if your lender actually credits the extra payment to principal. Some lenders hold extra payments in escrow or apply them to your next month's regular payment instead. Before you start, contact your loan servicer and confirm in writing that extra payments go directly to principal with no prepayment penalty.

Key Takeaways

  • One extra mortgage payment per year typically shortens a 30-year loan by 4 to 6 years, depending on your interest rate and starting balance.
  • The interest savings range from tens of thousands to over $100,000 on a standard mortgage, with higher savings on loans with higher interest rates.
  • Your lender must apply extra payments to principal, not hold them or roll them into your next regular payment, so confirm this in writing before you start.
  • The biweekly payment method (paying half your monthly payment every two weeks) is the most common way to make one extra payment per year without disrupting your budget.
  • Extra payments reduce your loan balance immediately, so you build equity faster and pay less interest on every remaining payment.

How the math works: principal reduction and interest savings

Your mortgage payment is split between principal and interest. 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 it goes to principal, you are reducing the balance that future interest is calculated on.

On a $300,000 loan at 6.5 percent over 30 years, your regular monthly payment is roughly $1,896. That first payment includes about $1,625 in interest and $271 in principal. If you make one extra $1,896 payment in year one and it goes to principal, you have reduced the loan balance by $1,896 plus the principal portion of 12 regular payments. That smaller balance means every remaining payment includes slightly less interest and slightly more principal, which accelerates the payoff.

The compounding effect is why timing matters. An extra payment made in year one saves interest for 29 more years. An extra payment made in year 15 saves interest for only 15 more years. The earlier you start, the more interest you prevent from accruing.

Biweekly payments: the easiest way to make one extra payment per year

The most common method is switching to biweekly payments: you pay half your regular monthly payment every two weeks instead of the full amount once a month. Since there are 26 biweekly periods in a year and only 12 months, you end up making 13 half-payments, which equals one full extra payment annually.

If your regular payment is $1,896 per month, your biweekly payment becomes $948. Over 26 pay periods, that totals $24,648, which is one extra $1,896 payment compared to the $22,752 you would pay in 12 monthly installments. Many employers allow you to align payroll deductions with biweekly pay cycles, making this method painless.

Some lenders offer biweekly payment plans directly; others require you to make manual extra payments. If your lender does not offer biweekly payments, you can simply send an extra payment once a year (often in December or whenever you receive a bonus) and specify that it goes to principal. Do not use a third-party biweekly payment service that charges a fee—the savings from one extra payment are real, but they are not large enough to justify paying $300 to $500 annually to a middleman.

Confirm your lender will apply extra payments to principal

Before you make any extra payment, call your loan servicer and ask three specific questions: (1) Do you accept extra principal payments? (2) Will you apply them directly to the loan balance, or will they be held in escrow or applied to my next regular payment? (3) Is there a prepayment penalty on this loan?

Get the answer in writing—an email from the servicer or a note in your online account. Some older mortgages include prepayment penalties that charge you a fee if you pay off the loan early; these are rare now, but they exist. If your loan has one, the penalty may outweigh the interest savings from extra payments, and you should calculate the break-even point before proceeding.

If your servicer refuses to apply extra payments to principal or charges a fee, consider switching servicers if your loan is portable, or simply skip this strategy. A lender that will not let you pay down principal faster is not worth fighting.

The difference between one extra payment and larger lump sums

One extra payment per year is a steady, budget-friendly approach. If you have the cash flow for a larger lump sum—say, $5,000 or $10,000 in a single payment—that saves more interest in less time. A $10,000 principal payment made in year one saves roughly $20,000 to $30,000 in interest over the life of the loan (depending on rate), compared to $60,000 to $80,000 saved by one extra $1,896 payment per year over 30 years.

The trade-off is flexibility. One extra payment per year is easy to budget for if you align it with biweekly pay or a predictable bonus. A lump sum requires you to have cash on hand and be willing to tie it up in the mortgage rather than keeping it liquid for emergencies. Most financial advisors suggest building a 3- to 6-month emergency fund before making large extra mortgage payments, because a mortgage is harder to borrow against than a credit line or savings account.

If you have high-interest debt (credit cards, personal loans), paying that down first usually saves more money than extra mortgage payments, because the interest rate is higher. Once high-interest debt is gone, extra mortgage payments become a reasonable use of surplus cash.

When extra payments do not make sense

Extra mortgage payments are not the right move if you have a very low interest rate (below 3 percent). The opportunity cost of tying up cash in the mortgage instead of investing it in the stock market or a high-yield savings account may be higher than the interest you save. A 2.5 percent mortgage rate means you are paying $2.50 per year per $100 borrowed; if you can earn 4 or 5 percent in a savings account or index fund, you come out ahead by not paying extra.

Extra payments also do not make sense if you are underwater on the mortgage (owe more than the home is worth) or planning to sell within 5 years. The interest savings take time to materialize, and if you sell before the payoff is accelerated significantly, you lose the benefit. Similarly, if you are in a variable-rate ARM (adjustable-rate mortgage) that is about to reset to a much higher rate, focus on refinancing first; extra payments on a soon-to-be-expensive loan are less valuable than locking in a better rate.

How to track your progress and stay motivated

Most loan servicers show your principal balance online. After each extra payment, check your account to confirm the payment was applied to principal and your balance decreased by the amount you sent. If it did not, contact the servicer immediately and ask why.

Some people find it motivating to calculate how many months or years they are shaving off the loan. Online mortgage calculators let you enter your loan details and compare the payoff date with and without extra payments. Seeing that you are cutting 4 to 6 years off a 30-year mortgage can reinforce the habit of making that annual extra payment, especially in years when cash flow is tight and you are tempted to skip it.

Keep records of every extra payment you make. If you ever refinance, sell, or dispute your loan balance, documentation of extra payments protects you. A simple spreadsheet with the date, amount, and confirmation number for each extra payment is enough.

Frequently Asked Questions

Will making one extra payment per year hurt my credit score?

No. Paying down your mortgage faster improves your credit over time because it lowers your debt-to-income ratio and shows you are managing debt responsibly. Your credit score may dip slightly the moment you make a large payment (because your available credit changes), but it recovers within a month or two.

Can I stop making extra payments if I need the money later?

Yes. Extra payments are voluntary; you are not locked into a contract to make them. If you hit a financial rough patch, you can return to regular monthly payments with no penalty. The extra principal you have already paid stays on the loan balance and continues to save you interest.

What if I refinance—do I lose the benefit of extra payments I already made?

No. Extra payments reduce your loan balance, so when you refinance, you are refinancing a smaller amount. If you paid down $20,000 in principal over five years, your new loan is $20,000 smaller, and you start the refinance process with that lower balance. You do not get the interest savings back, but you keep the principal reduction.

Is one extra payment per year better than paying extra toward principal every month?

The math is the same: one extra payment per year equals roughly 8 percent extra principal paid annually. Whether you make it in one lump sum or spread it across 12 smaller extra payments does not change the total interest saved. Choose the method that fits your budget and cash flow.

What if my lender will not let me make extra payments without a fee?

Switch lenders if possible, or skip this strategy. A fee that eats into your interest savings defeats the purpose. Some credit unions and online lenders are more flexible about extra payments than traditional banks; if you are unhappy with your current servicer, shopping around is worth your time.