EMI or prepayment: where a home-loan rupee actually goes

An EMI is a fixed payment covering that month's interest plus whatever remains. In month one of a ₹40 lakh loan at 8.75%, the interest alone is about ₹29,167. If the EMI is about ₹35,300, only roughly ₹6,100 goes to the principal — 17% of the payment.

Twenty years later the ratio has inverted: nearly all of the payment reduces the balance. The total interest over the loan works out to roughly ₹44.7 lakh on a ₹40 lakh loan, which is more than the amount borrowed.

This is not a flaw in the loan, it is arithmetic: interest is charged on the outstanding balance, and the balance is largest at the start.

A prepayment removes principal, and every rupee of principal removed stops accruing interest for the entire remaining term. That is why one early prepayment outperforms almost any safe investment over the same horizon.

Prepaying ₹1 lakh in year three of a 20-year ₹40 lakh loan at 8.75% typically saves ₹3.5–4 lakh in interest and shortens the loan by around a year — depending on whether the lender reduces the tenure or the EMI. Reducing the tenure is almost always the better choice if you can afford the payment; reducing the EMI lowers your immediate obligation but gives back much of the saving.

The same ₹1 lakh in a fixed deposit at 7% over the same 17 years grows to about ₹3.2 lakh, and that gain is taxable. The comparison is not close.

Prepayment is a good default and a poor absolute rule. Four situations where it is not:

• You have no emergency fund. Keeping three to six months of expenses liquid is worth more than the interest saved, because the alternative is a personal loan at 14% when something breaks.
• You have higher-interest debt. Credit-card and personal-loan rates dwarf a home loan. Clear those first, always.
• The loan has a prepayment penalty and you are switching instead. Floating-rate home loans to individuals generally carry no penalty now, but fixed-rate products can — check before you pay.
• You are close to the end of the term. In the last few years of a 20-year loan almost the entire EMI is principal, so prepayment saves very little interest. The calculator will show this plainly if you look at the amortisation table near the end.

Work an example. A 40 lakh loan at 8.75% over twenty years costs 35,348 a month, and total interest across the life of the loan is roughly 44.8 lakh — more than the amount borrowed. In month 37 the outstanding balance is about 37.47 lakh and the interest charged that month alone is about 27,300.

Now prepay 1 lakh in month 37 and keep the EMI unchanged. Because the lender keeps collecting the same amount against a smaller balance, the loan closes about twelve months earlier and the interest saved is roughly 3.2 lakh. Note what did not change: your monthly outgo. The saving comes from time, not from paying more every month.

That is the benchmark for comparing against investing the same 1 lakh. A guaranteed, tax-free saving of 3.2 lakh over the remaining term is what an investment has to beat, and the comparison belongs after tax on both sides — interest avoided is not taxed, while investment gains usually are.

The other lever is reducing the EMI rather than the tenure. It lowers the monthly obligation and saves very little by comparison. If being free of the debt is the goal, keep the EMI and shorten the term.

There is also a legitimate non-financial argument. Some people sleep better with a smaller balance, and a decision that improves your behaviour consistently is worth more than one that looks optimal on a spreadsheet. What is not defensible is prepaying away your emergency fund, or prepaying a loan at 8% while carrying a card balance at 40%.

• Emergency fund first: three to six months of expenses in a liquid account. Prepaying with no buffer converts a liquidity problem into a fresh loan later, usually at a worse rate.
• Clear the most expensive debt first. A credit card at 36% or more, or a personal loan in the teens, beats any mortgage prepayment decision every time.
• Then the home loan, if its rate is higher than what you can reliably earn after tax on a low-risk instrument.
• Then investments, if you are young, the rate is low and the horizon is long — with the reminder that market returns are not promised while an interest saving is.

Home loans in India are almost always floating, and that changes the comparison. When the repo rate moves, the lender resets your rate and usually keeps the EMI the same, extending the tenure instead. A prepayment made early, while rates are high, saves at the high rate for the remaining term; the same money prepaid after a rate cut saves less.

It also means the interest figure in your sanction letter is not the interest you will pay. A twenty-year loan that stays at 8.75% for its whole life is a theoretical object, not a plan. Download the amortisation schedule from your lender, check the current reset rate, and recompute before deciding — the number that matters is the rate you are paying now, applied to the balance that exists now.

One practical check before any prepayment: confirm whether your lender charges a foreclosure or prepayment fee. For floating-rate home loans to individuals, the regulator has long prohibited such charges, but fixed-rate loans and some non-individual products can carry them, and a fee can erase a year of interest saving on a small prepayment.