One Extra Mortgage Payment a Year: What It Actually Saves

Here is the same $400,000 loan at 6.5% over 30 years under five different prepayment strategies. The baseline monthly principal and interest payment is $2,528.27.

The leverage comes from where an early-mortgage payment actually goes. On that $400,000 loan at 6.5%, the very first monthly payment of $2,528.27 splits roughly like this:

In month one, about 86% of your payment is interest. Every extra dollar you send early skips that entire interest stack — it goes straight to principal, permanently removing that dollar from the balance that generates interest for the remaining 359 months.

This is why the same $2,528 is worth far more in year 2 than in year 20, and why the "start now, even small" advice is mathematically sound rather than just motivational. $100 a month — a genuinely modest amount — still saves $63,917 and pulls the payoff forward by more than three years.

The mechanics matter more than people expect, and this is where money gets misapplied.

1. Specify "apply to principal" explicitly. This is the step that goes wrong. Extra money sent without instruction is frequently applied to your next scheduled payment instead of your principal balance. That doesn't save you interest — it just pays you ahead, and some servicers will then skip drafting your next autopay. Use your servicer's dedicated "additional principal" field if one exists.
2. Verify it landed. Check your next statement. Your principal balance should have dropped by the full extra amount, and your next payment should still be due as normal.
3. Set it up as recurring. Most servicers allow a standing extra-principal amount. Automating $210.69 a month is far more reliable than intending to make a lump payment each December.
4. Check for a prepayment penalty first. Rare on modern conforming mortgages but not extinct — see below.
5. Don't confuse your payoff amount with your principal balance. A payoff quote includes accrued interest through the payoff date and any fees, so it's slightly higher than your principal balance. If you're making a final large payment, request an official payoff quote with a good-through date.

Before committing to a prepayment plan, confirm your loan permits it without charge. Most modern mortgages do, but the exceptions are worth checking rather than assuming.

• Qualified Mortgages under federal rules face tight restrictions on prepayment penalties, and most conforming loans originated in recent years carry none at all.
• FHA, VA and USDA loans do not permit prepayment penalties.
• Some non-QM, portfolio, investor and older loans may include one, often on a declining schedule over the first few years — the structure sometimes described as "5-4-3-2-1," meaning the penalty percentage steps down annually.

Your note is the authoritative document. Search it for "prepayment," and if the language is ambiguous, ask your servicer to confirm in writing. The Consumer Financial Protection Bureau's guidance on prepayment penalties explains what lenders may and may not charge.

Prepaying a mortgage is a guaranteed, risk-free return equal to your interest rate. At 6.5%, that's a genuinely strong risk-adjusted return — better than most bonds, with zero volatility. At 3%, it's a much weaker case against almost any diversified alternative.

Reasons to prioritise something else first:

• Higher-rate debt. Credit cards at 22% dominate a 6.5% mortgage by a wide margin. Clear those first.
• No emergency fund. Money in your mortgage is illiquid. Getting it back requires a HELOC application, a cash-out refinance or a sale — none guaranteed to be available when you need them.
• Unmatched employer retirement contributions. A 50% or 100% match is an immediate return no mortgage rate competes with.
• A very low rate. If you hold a 2.75% or 3.25% note, the arithmetic case for prepaying is weak. That said, the certainty has real value to some people, and that's a legitimate preference rather than a mistake.

How much does one extra mortgage payment a year save?

On a $400,000 loan at 6.5% over 30 years, about $111,979 in interest, with the loan paid off 5.7 years early. The saving scales with your rate and balance — higher rates make prepayment substantially more valuable.

Is it better to pay extra monthly or once a year?

Monthly, and by a meaningful margin. Splitting one extra annual payment into twelve monthly additions saves about $4,362 more on the example above, for identical total outlay, because each dollar reaches your principal up to eleven months sooner.

How much does paying an extra $100 a month on a mortgage save?

On that same $400,000 loan at 6.5%, about $63,917 in interest, with payoff arriving 38 months — just over three years — early. It's a striking return for a modest, sustainable amount.

What if I make two extra mortgage payments a year?

Roughly $179,568 saved on the example loan, with payoff in 20.8 years instead of 30. The returns keep scaling, though each additional payment adds slightly less than the one before it.

Does paying extra on your mortgage lower your monthly payment?

No. Extra payments shorten the loan term but leave your required monthly payment unchanged. Only a mortgage recast reduces the required payment, and it saves substantially less interest in exchange.

Will my lender let me pay extra principal?

Almost certainly. FHA, VA and USDA loans prohibit prepayment penalties outright, and most modern conforming mortgages carry none. Some non-QM, portfolio and older loans may include one — check your note for the word "prepayment" before making a large payment.

Is the payoff amount the same as the principal balance?

No. A payoff quote includes accrued interest through the payoff date plus any applicable fees, so it's slightly higher than your principal balance. If you're paying the loan off entirely, request an official payoff quote with a good-through date rather than working from your statement balance.