Loan Prepayment: How One Extra Payment Changes the Whole Schedule

A loan payment does two things at once: it pays the interest that accrued this month, and it reduces the principal. Early in the loan the first part dominates, which is why the balance falls so slowly at the start.

A prepayment does only the second thing. Every rupee goes straight to principal, and that rupee then stops accruing interest for every remaining month of the loan. That is why the saving is so disproportionate to the amount.

Why the saving is so large

Consider a ₹50,00,000 home loan at 9% over 20 years. The EMI is about ₹44,986, and over 240 months you repay roughly ₹1.08 crore, of which about ₹58 lakh is interest.

Now pay one extra ₹1,00,000 at the end of year two, with the tenure reduced rather than the EMI.

That ₹1 lakh would otherwise have sat in the balance accruing 9% for the remaining 18 years. Removing it early does not save you ₹9,000 a year for one year. It saves ₹9,000 a year, compounding, for the rest of the loan, and it brings the final payments forward, which removes their interest entirely. The total interest saved lands around ₹3.4 lakh, and the loan finishes roughly five months early.

A ₹1 lakh prepayment returning ₹3.4 lakh is not exotic. It is what a 9% rate does over eighteen years.

Timing beats size

The same ₹1 lakh has very different effects depending on when it lands:

Figures are illustrative and depend on the exact schedule, but the shape is the point: the value of a prepayment decays steadily as the loan progresses. Prepaying in the final years is close to pointless, because there is barely any remaining interest left to cancel. If you are going to do it, do it early.

A small monthly extra vs one lump sum

Adding a modest amount to every instalment is usually easier to sustain than saving up for a lump sum, and it works out similarly well because the extra starts biting immediately and keeps biting.

On the same loan, an extra ₹5,000 every month, roughly 11% on top of the EMI, removes about four years from the tenure and saves in the region of ₹15 lakh of interest. Our EMI Calculator has an extra monthly payment field so you can put your own numbers against that.

Check three things first

The penalty clause. Floating-rate home loans to individuals cannot carry one. Personal loans, car loans and fixed-rate products often can, and a 3% charge on the amount prepaid eats a meaningful share of the benefit. Some agreements also bar prepayment for the first six or twelve months.

What the lender does by default. Reducing the tenure saves much more than reducing the EMI. Most lenders reduce the tenure automatically, but not all, and a rate change can quietly extend your loan without changing your instalment. Ask for the revised end date in writing after any prepayment or rate revision.

Whether the money has a better job. Prepaying is a guaranteed return equal to your loan rate. Against a 14% personal loan, almost nothing beats it. Against a home loan at 8.5% where you also claim Section 24(b) interest relief, the effective cost may be nearer 6%, and an emergency fund or an employer-matched retirement contribution can be the better use of the same rupee.

The Prepayment Calculator will show you the interest saved and months removed for your own loan, and reading an amortisation schedule explains why the early payments are so interest-heavy in the first place.