Make a lump-sum prepayment on a loan and the lender asks a question: do you want to reduce the EMI and keep the same end date, or keep the EMI and finish earlier?
Most people choose the lower monthly payment, because it feels like the immediate benefit. It is usually the more expensive choice by a wide margin.
Why interest works the way it does
Interest each month is charged on the outstanding balance. Early in a loan, the balance is large, so most of your payment is interest and very little touches the principal.
On a 25-year home loan at 8.5%, roughly 70% of the first year's payments are interest. Only in the later years does the balance shrink fast.
This has one important consequence: a rupee of principal removed early saves far more interest than the same rupee removed later, because it removes that balance from every remaining month's calculation.
Worked example
A loan of ₹50,00,000 at 8.5% over 20 years:
- EMI: ₹43,391
- Total paid: ₹1,04,13,879
- Total interest: ₹54,13,879
You pay more in interest than you borrowed. That is normal for a long loan at this rate.
Now suppose after year 3 you prepay ₹5,00,000.
| Option | New EMI | Term left | Interest saved |
|---|---|---|---|
| Reduce EMI | ₹38,977 | 17 years (unchanged) | ≈ ₹9,00,000 |
| Reduce tenure | ₹43,391 (unchanged) | ≈ 13 yrs 10 mo | ≈ ₹19,40,000 |
Reducing the tenure saves roughly twice as much.
The reason is straightforward. Reducing the EMI lowers each payment but keeps you in debt for the full remaining 17 years, so interest keeps accruing on a balance that shrinks slowly. Reducing the tenure keeps the same payment against a smaller balance, so a larger share goes to principal every month, and the loan ends more than three years early.
Run your own numbers with the loan EMI calculator — the amortisation schedule shows the interest-versus-principal split month by month, which makes the effect visible.
When reducing the EMI is the right call
The tenure option is not automatically correct. Lower the EMI when:
- Your income has dropped or become uncertain. A smaller committed outflow is worth real money as insurance. Cash flow beats optimisation when the downside is missing a payment.
- You have higher-interest debt. Freeing up ₹4,400 a month to attack a credit card at 36% beats saving 8.5% on the mortgage. Always clear the expensive debt first.
- You would otherwise be forced to borrow again. Draining savings into a prepayment and then taking a personal loan at 14% is a net loss.
The general rule: reduce tenure if your income is stable, reduce EMI if it is not.
Timing matters more than amount
Because interest is front-loaded, *when* you prepay matters as much as how much.
On the same ₹50 lakh loan, a ₹5,00,000 prepayment saves roughly:
| Prepaid in | Interest saved (tenure reduction) |
|---|---|
| Year 1 | ≈ ₹21,50,000 |
| Year 3 | ≈ ₹19,40,000 |
| Year 10 | ≈ ₹9,80,000 |
| Year 15 | ≈ ₹4,10,000 |
The same money saves five times more in year one than in year fifteen. If you are planning to prepay at all, earlier is substantially better.
The comparison people forget
Prepaying is effectively a risk-free, tax-free return equal to your interest rate. Paying down an 8.5% loan is equivalent to an investment returning 8.5% guaranteed.
So the honest question is not "should I prepay?" but "can I reliably beat 8.5% after tax, with this level of certainty?" Equity might average more over decades, but not risk-free and not guaranteed over your specific time horizon. A fixed deposit at 7% pre-tax does not beat it.
There is a tax angle in some jurisdictions — home loan interest deductions can lower the effective rate. If you claim such a deduction, use the post-deduction effective rate in the comparison, not the headline rate. The percentage calculator is useful for working that through.
Before you prepay: check the terms
- Prepayment penalties. Many jurisdictions bar them on floating-rate home loans, but fixed-rate loans, personal loans and car loans often charge 2–4%. A 3% penalty on ₹5 lakh is ₹15,000 — it can still be worth it, but do the sum.
- Get the reduction option in writing. Some lenders default to reducing the EMI unless you explicitly ask otherwise. Confirm which you are getting before the money moves.
- Keep your emergency fund. Prepayment is irreversible; you cannot withdraw it back out. Six months of expenses stays liquid first.
- Ask for a revised schedule. After prepaying, get the updated amortisation table and verify the new end date matches what you agreed.
Frequently asked questions
Does prepayment reduce the interest already charged?
No. It reduces future interest by shrinking the balance from now on. Interest already accrued is settled.
Is one large prepayment better than several small ones?
Earlier beats larger. Several small prepayments made sooner usually beat one large one made years later.
Should I prepay or invest?
Prepaying returns your interest rate, guaranteed and tax-free. Compare against what you can earn *after tax and adjusted for risk*, not against a headline market return.
Does part-payment change my credit score?
Closing a loan early is neutral to mildly positive. Reducing utilisation and finishing without missed payments both help.
How do I model this myself?
The [loan EMI calculator](/loan-emi-calculator) gives the amortisation schedule; the [compound interest calculator](/compound-interest-calculator) models what the same money would do if invested instead.
Related reading
The compound interest calculator shows the other side of this trade — what the prepayment amount would grow to if invested. For quick rate comparisons, the percentage calculator handles increases, decreases and effective rates.