Sukanya Tracker12 September 2026
Deposit by the 5th: the SSY rule that costs parents a month at a time
Interest is calculated on the lowest balance between the 5th and the end of the month. Here is what that means, with numbers, and how to never lose a month again.
Post-office savings schemes — the SSY, PPF and others — calculate interest each month on the lowest balance between the 5th and the last day of the month. It sounds like accounting trivia. It decides whether your deposit earns this month or next.
What actually happens
Say you deposit ₹12,500 on the 3rd of October. The balance from the 5th to the 31st includes it, so October’s interest is calculated on it.
Deposit the same ₹12,500 on the 8th of October instead. The lowest balance between the 5th and the 31st is the balance before your deposit — so October’s interest ignores it. The money starts earning in November.
At 8.2%, one month’s interest on ₹12,500 is about ₹85. On ₹1,50,000 it is ₹1,025.
Why it adds up
Nobody loses a fortune in one month. The cost is that the habit repeats, and the lost interest never compounds:
| Habit (₹1.5 lakh a year for 15 years, 8.2%) | Value at 21 |
|---|---|
| Monthly, on or before the 5th | ≈ ₹69.3 lakh |
| Monthly, after the 5th | ≈ ₹68.9 lakh |
About ₹45,000 over the life of the account, from the same money, for depositing a few days later each month.
The practical rule
- If you deposit monthly, do it on the 1st to the 5th. Set a standing instruction for the 1st, so a delay of a day or two still lands in time.
- If you deposit by cheque or NEFT, allow for clearing: aim for the 1st or 2nd.
- Once a year, the same rule has a bigger cousin: deposit in the first week of April and the money earns all twelve months. The best time of year to deposit →
Sukanya Tracker shows you, as you record a deposit, whether it earns this month or next — and reminds you on the 1st and again on the 4th if the month’s deposit is still unpaid. Get the app →