Prepay Your Home Loan or Invest? How to Decide

You have a lump sum — a bonus, an incentive, a matured deposit — and a home loan running for another sixteen years. Put it against the loan, or invest it? The honest answer is that this is a comparison of two returns, one certain and one not, and a few details decide which way it tips.

Nothing here is financial advice. It is the arithmetic, so you can do the sum with your own numbers.

The core comparison

Prepaying a loan earns you a guaranteed return equal to your loan's interest rate. Prepay ₹3,00,000 against a loan at 8.5%, and you have saved yourself 8.5% a year on that money, with certainty, for as long as the loan would have run.

Investing might earn more. Equity has historically done better than 8.5% over long periods, and might do far worse over any particular five years. So the real question is: is the extra expected return worth the uncertainty, given where you are?

Two adjustments make the comparison fair.

Adjust for tax on both sides

On the loan. If you claim a deduction on home-loan interest, your effective borrowing cost is lower than the sticker rate. Under the old tax regime, interest on a self-occupied home has been deductible up to ₹2,00,000 a year under Section 24(b), and principal repayment counts within the ₹1,50,000 of Section 80C. The newer default regime does not offer those deductions for a self-occupied property. Which applies depends on the regime you have chosen, and the rules change — check the current position or ask your CA before relying on it.

On the investment. Compare after-tax with after-tax. A debt fund or fixed deposit is taxed differently from equity held for years, and the headline return is not what reaches you.

A rough way to think about it: if your loan costs 8.5% and you get no deduction, you need an after-tax return above 8.5%, reliably, for investing to win. If a deduction brings your effective cost to around 6%, the bar drops, and investing becomes the stronger bet for long horizons.

Do these first, whatever the answer

1. Clear expensive debt. Credit card balances at 36–48% and personal loans in the teens beat both options. This is not close.
2. Fund the emergency account. Three to six months of expenses, somewhere you can reach in a day. A prepayment cannot be withdrawn when the car needs a gearbox.
3. Buy the insurance you lack. Term cover and health cover protect the plan itself.

Only after those does prepay-versus-invest become an interesting question.

Why timing changes the answer

In a reducing-balance loan, early instalments are mostly interest. A prepayment in year three removes years of future interest; the same amount in year fifteen removes very little, because by then most of what is left is principal.

Run your own figures in the EMI calculator — it shows the interest saved and the months removed, and it lets you compare keeping the EMI against lowering it.

That choice matters as much as the amount:

• Keep the EMI, shorten the tenure. The loan ends sooner and the interest saved is much larger.
• Keep the tenure, lower the EMI. Less saved overall, but every month gets easier, which is the right answer when cash flow is tight.

Where prepaying usually wins

• Your loan rate is high relative to safe returns, or you get no tax deduction on interest.
• The loan is young, so most of the interest is still ahead of you.
• A large EMI is crowding out everything else you want to do.
• Volatility keeps you awake. A guaranteed 8.5% you can sleep through beats a theoretical 12% you panic-sell out of.

Where investing usually wins

• Your effective loan cost is low after deductions.
• Your horizon is long — ten years or more — and you will not touch the money.
• You are still building the habit of investing; a monthly SIP you never miss is worth more than a one-off prepayment.
• Your loan is small and nearly over.

The split most people should consider

There is no prize for purity. Splitting a bonus — half against the loan, half invested — captures some certain return, keeps the investing habit alive, and removes the regret of having guessed wrong. It is rarely the mathematically optimal answer, and it is very often the one people stick to.

Before you prepay, check three things

• Charges. Many floating-rate loans to individuals carry no prepayment charge; fixed-rate loans often do. Ask before you transfer.
• What the bank does by default. Some lenders reduce the EMI automatically unless you ask for the tenure to be cut instead. Say which you want, in writing.
• The paperwork afterwards. Get the revised schedule, and check the outstanding balance and remaining instalments have changed the way you expected.

Then record it. Becom's budget planner carries each loan forward month by month and advances it by one instalment, so the outstanding figure you see is current rather than remembered — and a prepayment shows up as a shorter loan rather than a number you have to recalculate every time you wonder.