Prepaying a loan: what actually saves the most

Why timing matters more than amount

Interest is charged on the outstanding balance. Early in a loan, that balance is near its maximum, so every rupee of principal you remove avoids years of interest on it. The same prepayment in the final year removes almost nothing, because there is barely any interest left to avoid.

This is the single most useful thing to know about prepayment: the earlier it happens, the more it is worth. A modest prepayment in year two can be worth more than a large one in year fifteen.

Reduce the EMI or reduce the tenure?

After a prepayment, lenders typically offer two choices. Keeping the EMI the same and shortening the tenure saves the most interest, because you keep paying at the original rate against a smaller balance and finish sooner.

Reducing the EMI and keeping the tenure frees up monthly cash flow instead. You still save interest compared with not prepaying at all, but less than the tenure option would have saved. Choose it when your monthly budget is stretched.

Prepay or invest?

Prepaying a loan gives a guaranteed, risk-free return equal to the loan's interest rate. Investing might return more, but is not guaranteed. Compare the loan rate against a realistic after-tax return on the investment, not an optimistic one.

For a home loan at around 8.5% and an equity fund you hope will return 12%, the gap is real but so is the risk, and the loan rate is certain. Many people split the difference: prepay enough to stay comfortable, invest the rest.

Check the terms first

Floating-rate home loans to individual borrowers in India generally cannot carry prepayment penalties, but fixed-rate loans and many personal and business loans can. Check your sanction letter before making a large prepayment, and get written confirmation of the revised schedule afterwards.