Loan Prepayment: Should You Reduce Your EMI or Your Tenure?

When you make a lump-sum prepayment on a loan, most lenders let you choose: keep paying the same EMI and finish sooner, or keep the same end date and pay a lower EMI. Keeping the EMI and shortening the tenure almost always saves much more interest. Lowering the EMI is the better pick only when you need the monthly breathing room.

The example below puts numbers on that difference. The maths works in any currency, so the figures have no currency symbol.

The two options in plain words

Option A: keep the EMI, reduce the tenure. Your monthly payment stays the same. Because the balance is now smaller, the same payment clears it faster, and the loan ends early.

Option B: keep the tenure, reduce the EMI. The lender recalculates your EMI so the smaller balance is repaid over the original remaining months. You pay less each month, but for just as long.

Both options reduce the balance by the same amount on the day you prepay. The difference comes afterwards. In Option A you keep repaying principal at the old, faster pace, so the balance falls more quickly and you pay interest on a smaller amount for every remaining month.

Worked example: 300,000 prepaid on a 3,000,000 loan

The loan

• Amount: 3,000,000
• Rate: 9% a year, reducing balance
• Tenure: 20 years (240 months)
• EMI: 26,991.78

If you never prepay, the total interest over 20 years is 3,478,026.88. (The formula behind that EMI is explained in how loan EMI is calculated.)

The prepayment

After 5 years (60 EMIs), you receive a bonus and put 300,000 towards the loan.

By that point you have paid 1,280,718.19 in interest, and the outstanding balance is 2,661,211.47. After the prepayment it falls to 2,361,211.47, with 180 months left on the original schedule.

Without the prepayment, the remaining 180 months would cost 2,197,308.69 in interest. That's the figure both options are measured against.

Option A: keep the EMI at 26,991.78

Step 1: The balance of 2,361,211.47 is repaid at 26,991.78 a month at 9%.

Step 2: It is cleared in 143 months instead of 180. The 143rd payment is smaller, 22,967.91, because only a little balance is left.

Step 3: Interest over those 143 months comes to 1,494,589.01.

Interest saved: 2,197,308.69 − 1,494,589.01 = 702,719.68, and the loan ends 37 months (just over 3 years) early.

Option B: keep the tenure at 180 months

Step 1: The EMI is recalculated for 2,361,211.47 over 180 months at 9%.

Step 2: The new EMI is 23,948.98, which is 3,042.80 lower than before.

Step 3: Interest over the 180 months comes to 1,949,604.74.

Interest saved: 2,197,308.69 − 1,949,604.74 = 247,703.96. The loan ends on its original date.

Side by side

The same 300,000 saves about 2.8 times as much interest in Option A. For most people, reducing the tenure is the better use of a bonus, unless the lower EMI solves a real cash-flow problem.

Timing matters: prepay early if you can

Early in a loan, the balance is large and most of each EMI is interest, so every amount you knock off the principal avoids interest for many years. Here is the same 300,000 prepayment made at different points in the 20-year loan, choosing Option A each time.

A prepayment in year 5 saves nearly five times as much as the same amount in year 15.

When reducing the EMI makes sense

Option B isn't wrong. It is a trade of interest for flexibility, and sometimes that trade is worth it:

• Your income has dropped, or is about to, and the current EMI is a strain.
• Your income is irregular and a lower fixed commitment lowers the risk of missing payments.
• You have other debts at a higher interest rate and want to free up cash each month to clear them faster.

If your lender allows regular part-payments without charges, there is a middle path: take the lower EMI, then pay extra whenever you can. You keep the safety of a lower required payment while still cutting interest. Check the terms first, because not every loan allows this.

Prepayment penalties and rules

Before you prepay, read your loan agreement or ask the lender in writing. Terms vary widely by country, lender, and loan type, and they can change. Things to check:

• Is there a prepayment or foreclosure charge? Some loans charge a percentage of the amount prepaid. In some places, charges on certain floating-rate loans are restricted by regulation; in others they're common. Check your local regulator's rules.
• Is there a lock-in period during which prepayment isn't allowed or costs more?
• Is there a minimum or maximum prepayment amount, or a limit on how many times a year you can prepay?
• Which option is the default? Some lenders reduce the tenure automatically, others reduce the EMI. If you want a specific option, ask for it explicitly and get confirmation.
• Does prepaying affect any tax benefit you get on loan interest? Where such benefits exist, the rules are local and change over time.

A penalty doesn't automatically rule prepayment out. Compare the fee to the interest you'd save. A hypothetical 2% charge on 300,000 would be 6,000, which is small next to 702,719.68 saved.

When investing the money might win

The alternative to prepaying is to invest the lump sum. Prepaying a 9% loan earns you a guaranteed 9% a year, in the form of interest you don't pay. Investing only wins if your investment return, after tax and fees, beats that rate, and you accept the risk that it might not.

To make a fair comparison, take the 300,000 from the example and look 15 years ahead, to the original end of the loan. In the prepayment case, once the loan is cleared after 143 months, you invest the freed-up EMI each month until the original end date. In the investing case, the 300,000 goes into an investment and the loan runs its full course.

These figures are before tax and assume a constant return every month, which real investments don't deliver. They show the principle clearly:

• If your return is below the loan rate, prepaying wins.
• At exactly the loan rate, it's a tie.
• Above the loan rate, investing wins, by a margin that grows with time.

The catch is that the loan rate is certain and the investment return isn't. A 12% expected return might turn out to be 4%, or negative over a bad stretch. Prepaying is the risk-free choice. Investing is a bet that you'll beat your loan rate by enough to justify the uncertainty.

A sensible rule of thumb: the higher your loan rate, the stronger the case for prepaying. On a low-rate loan, with a long investment horizon and a tolerance for ups and downs, investing can be reasonable.

Before you prepay anything

• Keep an emergency fund. Money paid into a loan is hard to get back. Don't drain your savings to prepay. See how big an emergency fund should be.
• Clear expensive debt first. Credit card balances and other high-rate borrowing usually cost more than a home or personal loan.
• Check the effective rate. If your loan was quoted as a flat rate, its true cost is higher than the headline. See flat rate vs reducing balance interest.

Run your own numbers

The Finaiver Loan EMI Calculator doesn't have a prepayment input, but you can model both options with it:

1. Enter your original loan amount, annual rate, and tenure, and click Calculate EMI.
2. In the Amortization schedule, find the Balance column for the month you plan to prepay. Subtract your prepayment.
3. For Option B, enter that new balance, the same rate, and the remaining months (switch the tenure to Months). The Monthly EMI shown is your new EMI.
4. For Option A, enter the new balance and try shorter tenures in months until the Monthly EMI is just below your current EMI. In the example, 143 months gives 26,975.99, just under 26,991.78.

The calculator shows a dollar sign, but the numbers work in any currency.

For more on the trade-off between term and cost, read loan tenure vs total interest.

This article is general information, not financial advice.