Planning to invest in the Public Provident Fund (PPF) this financial year? Then aim to do it by April 5. While the investment limit and lock-in period stay the same, the interest benefit changes based on when you invest.

Here’s the catch—PPF interest is calculated on the lowest balance between the 5th and the last day of each month.

So, if you deposit money after the 5th, you miss out on interest for that month.

How timing affects your returns

Say you invest ₹1.5 lakh into your PPF account on April 6. If your previous balance was ₹1 lakh, the interest for April will be calculated only on ₹1 lakh—not on ₹2.5 lakh.

That’s a full month of interest lost on ₹1.5 lakh.

Now, imagine you invested that ₹1.5 lakh on April 4 instead. The entire ₹2.5 lakh would earn interest for April.

Over 15 years, that difference adds up.

Interest compounding makes timing even more powerful

The PPF offers 7.1% interest, compounded annually.

That means early investment doesn’t just earn you more interest—it also builds your future interest faster.

Even a one-month delay each year can shrink your final corpus.

If you prefer lump-sum PPF contributions, do it once—and do it before April 5. This way, your full investment enjoys interest for all 12 months of the financial year.

On the surface, the difference may look minor.

But over 15 years or more, those “small” interest losses compound.

So, timing the deposit can quietly supercharge your long-term gains, experts say.