The features of the post office PPF scheme details are as follows – 1. You can invest a minimum amount of Rs. 500 and a maximum amount of Rs. 1.5 lakhs in one financial year. 2. The minimum lock-in period of the PPF scheme account is of 15 years. However, you can get the tenure extended in multiple of 5 years as per your wish. 3. You cannot hold the PPF account jointly with your spouse or any other family member. However, you can appoint a nominee. 4. You have to compulsorily deposit a minimum of Rs. 500 in your PPF account every year to avoid your account from collapsing.