While setting up your IYI, you are required to mention if you choose to invest 100% of the interest earned or to the extent of the amount specified by you.
If you have chosen to invest 100% of the interest amount, IYI will automatically invest the credited interest amount each month, regardless of its size. This allows you to benefit from compounding over time, even if your monthly interest varies.
However, if you have chosen to invest a specific amount, then the investment shall be made for such amount only even if you have earned higher interest amount. However, if the interest amount credited is lesser than the amount specified by you, the investment for the particular month will be rejected. However, investments of consecutive months shall continue subject to the availability of such specified amount.