Extra payments toward your loan principal are one of the simplest ways to save money. You're not doing anything complicated—just sending more money and watching your payoff date move closer.
But it's not always the right move. Let me explain when it is and when it isn't.
How Extra Payments Work
When you make a regular mortgage or loan payment, part goes to interest (calculated on current balance) and part goes to principal (reducing the balance).
Extra payments skip the interest part and go straight to principal. This reduces your balance immediately, which means less interest accumulates going forward.
It's a virtuous cycle: lower balance → less interest → more of each future payment goes to principal → balance drops faster.
The Impact Is Bigger Than You Think
On a $300,000 mortgage at 6.5% for 30 years:
**Regular payments only**: $682,633 total paid (including $382,633 in interest)
**Extra $200/month from day one**: $599,000 total paid, loan paid off 6.5 years early, ~$83,000 saved
That extra $200/month totals about $56,000 over the shorter loan life—but saves $83,000. You come out $27,000 ahead.
When Prepayment Makes Sense
**High interest rates**: The higher your rate, the more impact extra payments have. At 7%, prepayment is very powerful. At 3%, much less so.
**Early in the loan**: Your balance is highest at the start, so interest costs are highest. Extra payments in year 1 save more than extra payments in year 25.
**No high-interest debt**: Paying extra on a 6.5% mortgage while carrying 22% credit card debt is backwards. Pay the cards first.
**Retirement match is maxed**: If your employer matches 401k contributions and you're not maxing that, do that first. It's a guaranteed 50-100% return.
**Emergency fund exists**: Don't drain savings to prepay. You need liquidity.
When to Skip Prepayment
Run the numbers for your situation: Use our free extra payment calculator to see exactly how much time and interest you save with additional payments.
**Low interest rate**: If your mortgage is 3.5% (locked in 2020-2021), you might earn more investing that money than you save prepaying.
**High-interest debt exists**: Attack expensive debt first.
**No emergency cushion**: Cash reserves matter more than slightly faster payoff.
**Investment returns look better**: At 6.5% mortgage rate versus 7-10% historical stock returns, it's close. At 3.5% mortgage versus 8% investments, investing wins mathematically.
Prepayment Strategies
**Fixed extra monthly payment**: Add $100, $200, or whatever fits your budget to each payment. Consistent and easy to track.
**Biweekly payments**: Pay half your monthly payment every two weeks. You make 26 half-payments = 13 full payments per year instead of 12. One extra payment annually without feeling the pinch.
**Annual lump sum**: Use tax refunds, bonuses, or windfalls for principal payments. Irregular but effective.
**Round up**: If your payment is $1,847, pay $1,900 or $2,000. Small but adds up.
Making Sure It's Applied Correctly
This is where people mess up. If you just send extra money without instructions, it might go to: - Next month's payment - Escrow account - Fees or late charges
You need to specify "apply to principal" or "principal reduction."
Check your lender's process. Some have online options. Others require writing it on the check or sending separate payments. After paying, verify on your next statement that the principal dropped by the extra amount.
The Recast Option
Some lenders offer "recasting" after a large principal payment. You pay a chunk (often $10,000 minimum), and they recalculate your payment based on the new lower balance.
This lowers your monthly payment for the remaining term. It's different from refinancing—no new loan, no closing costs, same rate and terms.
Useful if you want to reduce monthly obligations while keeping your low rate.
The Emotional Factor
Financially, there are scenarios where investing beats prepaying. But financially isn't everything.
Some people sleep better knowing they're paying off their home faster. Owning your home free and clear has psychological value that doesn't show up in spreadsheets.
If aggressive prepayment gives you peace of mind and you've covered the basics (emergency fund, retirement matching, no high-interest debt), it's a valid choice even if the pure math suggests investing.
My Simple Rule
If your mortgage rate is above 6% and you've handled the basics, prepayment is a solid choice.
If your rate is below 5% and you're comfortable with market risk, investing might win.
In between? It's personal. Both are reasonable.
Just make sure the money actually goes to principal. That's the part where people get tripped up.
