Advance tax, 15 December instalment: reminder messages to clients under the Income-tax Act, 2025

The December instalment is easy for clients to forget: it falls between the September rush and the year end, and most of them did nothing for it last month. This is also the first tax year under the Income-tax Act, 2025, so the sections have new numbers and the payment screen now asks which Act a payment is under. Five short messages over three weeks cover it.

What is due by 15 December

The Income-tax Act, 2025 came into force on 1 April 2026.¹ Its section 408 keeps the four instalments clients already know:³

Anything paid by 31 March still counts as advance tax for the year.³ 15 December 2026 is a Tuesday.

Which clients pay it

• Clients whose year's tax is ₹10,000 or more. Advance tax is payable only above that amount (section 404). It is worked out as the tax on the year's estimated income, less the tax that will be deducted or collected at source during the year (section 405).² A salaried client whose TDS covers the tax usually owes nothing. The clients to watch are the ones with interest, rent, capital gains or business income.
• Not senior citizens without business income. A resident individual aged 60 or more at any time in the tax year, with no income from business or profession, does not pay advance tax (section 403(3)).²
• Not in December for presumptive clients. A client who declares income under section 58(2), the scheme that replaced sections 44AD and 44ADA, pays the whole amount in one go by 15 March (section 408(2)).³⁶

Sorting your client list into these groups once is most of the work. Every message below goes to one group only.

What a shortfall costs

Two sections set the interest, in place of sections 234C and 234B of the old Act:⁴

• Section 425, for paying late in the year. If the advance tax paid by 15 December is less than 75% of the tax due on the income in the return, the client pays 3% simple interest on the shortfall. June and September are spared if 12% and 36% were paid. December has no such margin.
• Section 424, for paying too little overall. If the advance tax paid for the year is less than 90% of the assessed tax, the client pays 1% simple interest a month on the shortfall, from 1 April after the tax year until the income is assessed.

An example: a client's tax due on the return is ₹2,00,000, so 75% is ₹1,50,000. They paid ₹1,00,000 by 15 December. The shortfall is ₹50,000, and the interest under section 425 is 3% of that, ₹1,500.

One exception is useful in December. Section 425 charges no interest on a shortfall caused by capital gains or dividend income that could not be estimated earlier, as long as the tax on it is paid in a later instalment or by 31 March.⁴ A client who sells shares or property in January does not owe December interest for it.

How the client pays

Payment is through e-Pay Tax on the income tax e-filing portal. For this year, the client chooses the Income-tax Act, 2025, which opens the challan ITNS 280N, then New Payment, the Income Tax tile, and Advance Tax (100) as the type of payment.⁵ Each type of payment needs its own challan, so advance tax and self-assessment tax cannot be paid together.⁵

After paying, the 7-digit BSR code, the date and the challan serial number are under e-Pay Tax, Payment History.⁵ Our recommendation is to ask for those three, or the receipt itself, on the day of payment. You will need them for the return, as in our ITR documents checklist, and a client who has to find a receipt in July often cannot.

Ask before you message

WhatsApp's Business Messaging Policy says to message people only after they have given you their number and agreed to receive messages from you, and to respect any request to stop.⁷ Clients who said yes when they joined can get these reminders. For the others, send the same words by email.

Messages you can copy

Replace the words in brackets, and write them in English or Hindi, whichever the client uses. The dates are our recommendation: early enough to work out the amount, late enough that the figures are close to the year's.

All the year's other dates are in our compliance calendar, which sends a shorter version of the first message. The same style of reminder for GST returns is in our GST reminder templates, and for the TDS statements due in the same months, our TDS return checklist.

What can run by itself

• The groups: each client marked once as advance tax, presumptive, senior without business income, or covered by TDS, so the right message goes to each and nobody gets two.
• The figures request on 1 December, and a follow-up that names only what is still missing, as in our client reminders.
• The last-day reminder, sent on 14 December only to clients with no receipt on file.
• The receipts, read when they arrive and filed in the client's folder with the BSR code, date and challan serial number, as in our document processing.

What stays with your team

• The estimate. Working out the year's income from part-year figures is a professional judgment, and a partner signs off the amount before the second message goes.
• Clients whose year changed. A large sale, a lost contract or a new business needs a conversation, not a template.
• Clients who cannot pay in full. What they pay now, and the interest that follows, is a decision you make with them.

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