Public Provident Fund, which is a government-backed tax-efficient savings scheme with 15-year lock-in period, offers a current interest rate of 7.1% per annum. If a person invests ₹1.5 lakh annually at the current interest rate for 15-year tenure, the maturity amount will be ₹40.68 lakh on ₹22.5 lakh total investment, NDTV Profit stated. Notably, PPF interest rate is reviewed quarterly.