Missed Your June Advance Tax Payment? Here’s How to Use ChatGPT to Work Out What You Actually Owe Now, and What It’s Costing You.
Advance tax has four deadlines a year, not one, and most people only think about it when a due date has already passed. Here’s a simple ChatGPT-assisted worksheet to catch up, plus what’s changed under the new tax law for FY 2026-27.
If your total tax for the year comes to more than ₹10,000 after TDS, you’re expected to pay it in four instalments across the year, not in one lump sum when you file your return. Miss a payment, or pay less than required, and interest starts adding up automatically — no notice, no warning, just a growing number attached to your tax bill.
This is ChatGPT for advance tax planning at its simplest — a worksheet for working out where you stand right now, using ChatGPT to do the arithmetic while you make every real decision about your own numbers. It also covers what’s genuinely different this year: the penalty rules for missing a payment have new section numbers under the Income-tax Act, 2025. The actual rules haven’t changed.
📑 Table of Contents
- 01Advance tax FY 2026-27: the four payment dates
- 02ChatGPT for advance tax planning
- 03Part 1 — Estimate this year’s tax
- 04Part 2 — Check how much you should have paid by now
- 05Part 3 — Work out the interest on any shortfall
- 06Part 4 — Build your payment reminders for the rest of the year
- 07Three mistakes that cost people the most
- 08A worked example: catching up after missing June
- 09Advance tax questions people actually ask
- Advance tax is due in four parts: 15% by 15 June, 45% by 15 September, 75% by 15 December, and 100% by 15 March.
- Miss a payment and interest builds automatically — 1% a month under what’s now Section 425 for a late instalment, and 1% a month under Section 424 if you’re still short of 90% of your total tax by year end.
- These are the same old Section 234C and Section 234B rules — just renumbered under the Income-tax Act, 2025, which took effect from 1 April 2026.
- ChatGPT is genuinely useful for the arithmetic — estimating tax, checking shortfalls, calculating interest. It should never be the one deciding your actual income estimate for you.
Advance Tax FY 2026-27: The Four Payment Dates, in Plain Terms
Think of advance tax as paying your tax bill in four chunks across the year, instead of all at once when you file your return. By 15 June, you should have paid at least 15% of what you expect to owe for the whole year. By 15 September, that climbs to 45%. By 15 December, 75%. And by 15 March, the full 100%.
This only applies if your total tax for the year — after any TDS already deducted — comes to more than ₹10,000. Resident senior citizens aged 60 or above, who don’t run a business, are exempt from advance tax altogether.
Two separate penalties can apply if you fall behind. One instalment paid late or short brings interest at 1% a month on that specific shortfall, for up to three months. That’s what used to be called Section 234C, now Section 425 under the new Act. Separately, if your total advance tax paid by 31 March comes to less than 90% of your final tax bill, a second interest charge kicks in from 1 April until you actually pay. That’s the old Section 234B, now Section 424. These are two different penalties, and it’s genuinely possible to owe both at once.
Pro tip
There’s a lesser-known relief worth knowing. If you’ve paid at least 12% of your total tax by 15 June, or at least 36% by 15 September, no interest applies for that specific date. Even though it’s technically below the 15% or 45% target. It’s a small cushion, but it genuinely helps if you’re a few percentage points short rather than badly behind.
ChatGPT for Advance Tax Planning: The Four-Part Worksheet
Four parts: estimate your tax for the year, check how much you should already have paid, work out any interest on a shortfall, and set reminders for what’s left. ChatGPT handles the calculations at each step. You supply the actual income numbers, and you decide what to do about any gap it finds.
Part 1 — Estimate this year’s tax
Guessing your annual tax roughly, without actually adding up income from every source, is how most shortfalls happen. A freelance project or a bonus that wasn’t in the original estimate quietly pushes the real number higher.
What ChatGPT doesThis is AI for advance tax calculation at its simplest — I list every income source I actually expect for the year and ask ChatGPT to estimate the total tax under both regimes, so I can pick the lower one.
The promptCHECK
REQ’D
What I still check by hand
This estimate is only as good as the income figures you give it. Update it whenever a new client, bonus, or freelance project comes in during the year — a stale estimate from April is exactly what causes a real shortfall by December.
Part 2 — Check how much you should have paid by now
Working out whether you’re on track means comparing what you’ve paid against the cumulative percentage required for every date that’s already passed. It’s easy to get wrong if you’re only thinking about the most recent due date instead of all the ones before it.
Where ChatGPT helpsI give it my estimated annual tax and what I’ve actually paid so far, and ask it to check me against every due date that’s already passed.
What I ask forPart 3 — Work out the interest on any shortfall
Calculating exactly how much interest has built up on a missed instalment takes a careful month-by-month calculation — 1% a month, for up to three months, per shortfall. Most people just skip it and hope for the best.
ChatGPT’s partWith the confirmed shortfall from Part 2, I ask ChatGPT to calculate the actual interest owed so far.
Copy this inPart 4 — Build your payment reminders for the rest of the year
Remembering four dates spread across ten months, each with a different required amount, is exactly the kind of thing that quietly slips when work gets busy.
With ChatGPTI ask ChatGPT to turn the remaining due dates and amounts into a simple reminder list I can drop into a calendar.
Last one
Three mistakes that cost people the most
Estimating income once in April and never updating it. A new project or bonus mid-year changes the real tax owed, but the original estimate quietly stays on file, and the gap only becomes obvious in March. Forgetting Section 234B and 234C are separate penalties. Catching up by March doesn’t undo the interest already charged on a missed June or September date — the two penalties are calculated independently. Assuming the presumptive single-instalment rule applies to everyone. Only taxpayers under presumptive schemes pay everything in one March instalment; regular salaried and business income still follows all four dates.
A worked example: catching up after missing June
Someone estimated their FY 2026-27 tax at ₹4,80,000. The 15 June instalment required 15% of that — ₹72,000 — but they paid only ₹40,000, distracted by a work deadline. That’s a shortfall of ₹32,000 against the June requirement.
Running Part 3’s calculation: interest under Section 425 on that ₹32,000 shortfall, at 1% a month for three months, comes to ₹960. Not a huge number on its own, but it’s money added on top of tax already owed, for a payment that was genuinely affordable in June — it just wasn’t made. The lesson wasn’t to panic about ₹960. It was to make sure the September instalment, now due at 45% cumulative, gets paid correctly — so a second shortfall doesn’t stack a fresh interest charge on top.
The Dates Don’t Move. Whether You Track Them Does.
AI for advance tax planning genuinely speeds up the parts that are just arithmetic — the estimate, the shortfall check, the interest calculation, the reminders. It has no opinion on what your actual income will be this year, and it shouldn’t. Get the numbers from your own life, hand the maths to ChatGPT, and the four dates stop being something you dread and start being something you just handle.
