Prepay or invest — the comparison people make is the wrong one
Comparing a loan rate against an expected return ignores that one is certain and the other is not. The correct comparison, and why timing within the tenure matters more than either.
A bonus arrives. The home loan is at 8.5%, equity is expected to return 12%. The standard advice follows immediately: invest, the spread is in your favour.
That comparison is missing several things, and at least one of them changes the answer.
Start with the correct rate on each side
The loan side. 8.5% nominal. If you are on the old regime and claiming section 24(b) interest deduction at 30%, the effective cost drops towards 6%. Two conditions apply that people skip: you must be on the old regime, and the deduction on a self-occupied property is capped at ₹2 lakh a year. On a ₹50 lakh loan, first-year interest is around ₹4.2 lakh — so more than half of it gets no relief at all. And under the new regime there is no deduction on a self-occupied property, which means the effective rate is simply 8.5%.
Most borrowers are now on the new regime. For them the tax-adjusted loan cost argument does not exist.
The investment side. 12% is an expectation, not a rate. After a 12.5% long-term capital gains tax it is around 10.5%. After a 0.5% expense ratio, about 10%. And it is a distribution, not a number: the realised outcome over ten years might be 6%, or 16%.
So the real comparison is a guaranteed, risk-free, tax-free 8.5% against a probable but uncertain 10%.
Stated that way it is much closer, and it is no longer obvious.
What a guaranteed return is worth
Nothing else available to a retail investor offers a certain 8.5% after tax. A fixed deposit at 7.25% nets about 5% in the 30% bracket. VPF at 8.25% is exempt only within the ₹2.5 lakh contribution threshold. PPF is 7.1%.
Prepaying a home loan at 8.5% is, in risk-adjusted terms, an extraordinarily good fixed-income return. If you hold any debt allocation — and almost everyone should — prepaying the loan is strictly better than holding that allocation in deposits.
Which reframes the question usefully. It is not "prepay or invest in equity". It is "prepay, or hold debt instruments paying less than the loan costs". The first framing is a close call. The second is not.
Timing within the tenure dominates
This is the part almost every discussion omits, and it is larger than the rate spread.
Interest is charged on the outstanding balance, so a rupee prepaid removes interest for every remaining year. A prepayment early in the tenure removes an enormous number of those years. Late, it removes almost none.
₹5 lakh prepaid against a ₹50 lakh loan at 8.5% over twenty years, keeping the EMI unchanged:
| Prepaid in | Interest saved | Tenure reduced |
|---|---|---|
| Year 1 | ₹17.9 lakh | 43 months |
| Year 5 | ₹12.4 lakh | 33 months |
| Year 10 | ₹7.1 lakh | 22 months |
| Year 15 | ₹2.6 lakh | 11 months |
The same ₹5 lakh is worth seven times more in year one than in year fifteen.
So the honest answer to "prepay or invest" depends heavily on where you are in the loan. In years one to five, prepaying is frequently the better decision even against equity. In years fifteen to twenty, it rarely is — by then most of the EMI is principal, and there is little interest left to remove.
Reduce the tenure, not the EMI
If you do prepay, the lender will ask which you want. This choice is worth more than most people realise.
On that ₹42 lakh outstanding balance at 8.5% with sixteen years left, a ₹5 lakh prepayment:
- Keep the EMI, cut the tenure: roughly ₹14.5 lakh of interest saved, about 34 months removed.
- Keep the tenure, cut the EMI: roughly ₹5.6 lakh saved.
Nearly three times the benefit, for a decision made in a single conversation. Reduce the EMI only if your cash flow genuinely needs the relief; if you can afford the current payment, keeping it is close to free money.
Note also that many lenders default to reducing the tenure on floating-rate loans when rates rise, and reducing the EMI when you prepay — both of which favour them. Ask explicitly.
The charges
On a floating-rate home loan to an individual, the RBI prohibits foreclosure and prepayment charges. Fixed-rate loans, and loans to non-individuals, can and usually do carry 2% to 4%. Check which category yours is in — many borrowers assume "home loan" means "no penalty" and discover otherwise at the counter.
A workable rule
Always prepay above 12%. Credit cards, personal loans, consumer finance. There is no investment case against 42%.
Between 9% and 12% — car loans, some education loans — prepay first. The certain return beats the uncertain one at these rates.
Below 9%, in the first half of the tenure: prepay, and treat it as your debt allocation. Then invest everything else in equity.
Below 9%, in the last third of the tenure: invest. There is little interest left to save.
Never prepay before the emergency fund is complete. Money put into a home loan is extremely hard to get back out; a top-up loan takes weeks and requires you to still be employed. An emergency arriving after a large prepayment is how people end up borrowing at 16% against a house they just paid down.
And the part that is not arithmetic
Debt has a psychological cost that the spreadsheet does not capture. People who clear a home loan describe a change in how they think about work, risk and career choices that a marginally larger portfolio does not produce.
If being debt-free would let you take a lower-paying job you would rather do, or leave a bad employer, or sleep properly, that is worth something real. Just make the decision knowing what it costs, rather than believing it is also the optimal financial answer — which, in the second half of a cheap loan, it usually is not.
Where these figures come from
- Reserve Bank of India — Policy rates, lending and deposit regulation, credit card rules
Published by FinClamp. This guide is information, not financial advice — see the disclaimer.