Should you prepay your loan, and if you do, should you reduce the tenure (the loan's term: how long it runs) or the EMI (the fixed monthly payment)? A loan prepayment is any amount you pay on top of the schedule, and most lenders accept one. What they rarely show you is what that money does.
In most loans, a modest extra payment made early does far more than its size suggests, because of where it lands and when. Reducing the tenure saves the most interest; reducing the EMI makes each month lighter but saves less. On a flat-rate loan, prepaying can save no interest at all, so the kind of loan you have matters first.
Why one extra payment does double duty
Every scheduled loan payment is really two payments. One part is interest, the month's rent on what you still owe. The other is principal, the part that actually shrinks the debt.
Early in a loan, that split is lopsided: most of each EMI is rent and a little is progress. Nothing is wrong; that is what interest on a big balance costs, and it is why you can pay 12 EMIs and barely dent the number.
An extra payment works differently. It arrives outside the schedule, so it carries no interest share: the whole amount comes off the principal.
Each month's interest is worked out on what you still owe. So every month after the extra payment charges a little less rent and sends a little more of your EMI to the debt, right to the end of the loan.
One payment buys a lasting discount on every month that follows. On a long home loan the effect can look too big to be true. Pay 5,000 extra at the start of a 30-year loan of 300,000 at 7%, and you save over 33,000 in interest and finish 19 months sooner. The picture below draws that loan.
How much you save depends on your rate and how long the loan has left to run, and it is usually more than you would guess.
When to prepay your loan: early beats late
Because of how it works, timing matters a lot. A prepayment in year 1 of a 5-year loan gets its discount on every month that is left. The same amount in the final year buys almost nothing, because most of the interest has already been paid.
If prepaying is going to be your move, the best month is as soon as your emergency buffer is in place and your expensive debt, such as card balances, is gone. If you are past that point already, start with this month's payment.
Wealth Mutant, our personal finance app, sets up a loan you repay monthly the way its lender prices it: its schedule, its rate and the split inside every EMI. Its prepayment simulator works out what an extra amount, monthly or one-off, would save in interest and in months, starting from what you owe today. Each payment you record takes seconds and keeps the loan in view, and your bank login is never needed. The app is a one-time purchase.
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Buy — $99 onceFlat rate or reducing balance: which loan do you have?
Everything above assumes your lender charges interest on what you still owe. That is the reducing-balance loan, and it is how most home loans (mortgages) are priced, along with most personal and car loans. There is a second kind.
On a flat-rate loan the interest is calculated once, at signing, on the full amount you borrowed. The same interest is then charged every month for the whole term, however fast the balance falls. In many markets, some vehicle loans, finance for appliances and phones, and a good deal of microfinance lending are quoted this way.
Two ways to tell which one you are holding. Ask the lender for the repayment schedule and read the interest column: on a reducing-balance loan that number falls every month, and on a flat-rate loan it is usually the same in every row.
Or check the total, by multiplying the amount you borrowed by the annual rate and then by the number of years. If that matches the total interest on your agreement, the loan is flat. If the two tests disagree, go by the total. With neither in front of you, one question settles it: is interest calculated on the reducing balance, or on the original amount?
Check this first, because on a flat-rate loan an extra payment has nothing to bite on. Next month's interest was never computed from next month's balance, so cutting the balance early does not cut it, and the lasting discount described above never appears.
What remains is the lender's settlement policy. Ask for a quote to close the loan in full, and see how much of the remaining interest comes off the total. How much comes off depends on the lender, and in some countries on the law, and that answer is the whole decision.
Wealth Mutant's prepayment simulator prices a flat-rate loan as a flat-rate loan. It shows the months you would finish earlier and an interest saving of zero, with a note saying why.
It also reminds you to ask about the settlement charge, which no figure on the page includes. The lender's quote is still the number that decides it.
Should you prepay your loan, then reduce the tenure or the EMI?
Check the loan's prepayment terms
Most personal and car loans allow prepayment. Some charge a fee, and in some countries floating-rate loans (whose rate moves with the market) can't be charged one at all. A one-time fee is often outweighed by the interest saved early in the term, but check the numbers.
Make sure it goes to principal
When you pay, make sure it counts as a principal reduction and not as an advance on next month's EMI. Some lenders treat it as an advance unless you ask, which buys you nothing.
Choose: a shorter tenure or a lighter EMI
Lenders often offer two options. Reduce the tenure, and the EMI stays the same while the loan ends sooner, which saves the most interest. Reduce the EMI, and the end date stays while each month gets lighter. On the loan above, keeping the EMI saves over 33,000 in interest; lowering it, by about 33 a month, saves about 7,000.
The shorter tenure wins on the numbers; the lighter EMI can win in real life when money is tight. Wealth Mutant's simulator shows the shorter-tenure case: it keeps your EMI and counts the months saved.
Make it visible, then make it a habit
Watch the split shift in your own numbers: after an extra payment, the next month's interest the app posts is smaller. Seeing it once is what turns a one-off prepayment into a habit: a standing extra each month, or a rule that windfalls go to the loan first.
When prepaying is the wrong move
Prepaying isn't always the best use of money. If the loan is cheap, at a low single-digit rate, investing the extra may earn more than the interest you would save. And a prepayment that empties your emergency buffer saves interest at the cost of leaving you one surprise away from new debt, which is a bad trade.
Get the order right first: buffer, then expensive debt, and only then does prepaying compete fairly with investing for whatever is left. If you have several debts, avalanche vs snowball goes through which one to clear first.
But when a mid-rate loan is sitting on your chest at night, the simulator's second number, the months saved, matters more than any total: the loan ends sooner. Freedom has an end date, and one extra payment moves it.
To see it on your own loan, add it to Wealth Mutant as a scheduled loan, with what you still owe, the rate and the EMI, and open its Prepayment tab. The months saved is the number to watch, and the tour walks through the rest of the app.