PPF Investment: The lock-in period or maturity period on a PPF account is 15 years. But, even after this, you can continue your investment. Meaning, you get this facility in PPF that you can extend it for 5 years. PPF Investment: Anyone from a child to an elderly can invest in the Public Provident Fund … Continue reading PPF Investment: Invest just Rs 3000 and get Rs 15.91 lakh, See calculation