You worked out your tax, subtracted the TDS your clients deducted, and were ready to pay the difference. Then the computation added two more lines you were not expecting — interest under Section 234B and interest under Section 234C — and the number went up by tens of thousands of rupees.
This is the most predictable surprise in Indian freelancing, and it is entirely a function of arithmetic: your clients withhold at a rate far below the rate you are actually taxed at, so the shortfall was always going to be yours to fund. Understanding which of the two sections is charging you, and why, is what stops it happening again next year.
Which year? The section numbers below are the Income-tax Act 1961 ones, which govern FY 2025-26 (AY 2026-27). From tax year 2026-27 the Income-tax Act 2025 applies: the advance-tax threshold is s.404 (formerly 208), the instalments s.408 (formerly 211), and the interest ss.424/425 (formerly 234B/234C). The rates and dates carried over unchanged.
Why this hits freelancers and not salaried people
A salaried employee has tax deducted at their actual effective rate, month by month, by an employer who computes it properly. Nothing is left over at the end of the year, so no advance tax is due and no interest arises.
A freelancer has TDS deducted at a flat statutory rate that has nothing to do with their tax bracket. Professional fees are withheld at the 194J rate; marketplace income at the far lower 194-O rate. Both are a fraction of what a profitable year is actually taxed at once slabs, surcharge and cess are applied.
TDS is not your tax bill. It is a deposit against it — and for most freelancers a small one. The rest was always due during the year, in instalments.
234B vs 234C: what each section charges
People treat them as one line item. They are not, and they fail for different reasons.
| Section 234C | Section 234B | |
|---|---|---|
| Charges you for | Paying late within the year — missing an instalment date | Not paying enough by the end of the year |
| Trigger | Cumulative payment below the instalment threshold on its due date | Advance tax paid by 31 March is under 90% of assessed tax |
| Rate | 1% per month (statutory, Section 234C) | 1% per month (statutory, Section 234B) |
| Period | 3 months per missed instalment; 1 month for the final one | From 1 April after the year ends until the shortfall is paid (or your return is processed) |
The consequence of that last row is worth sitting with. 234B keeps running. It accrues from 1 April until the tax is paid, so every month you delay filing adds another 1% to a balance you already owe. If you are reading this in a panic during filing season, the cheapest action available to you is to pay sooner rather than to keep researching.
The advance tax instalment schedule 234C measures against
Advance tax becomes payable under Section 208 (s.404 from tax year 2026-27) once your assessed tax — tax for the year less TDS — reaches Rs. 10,000. Above that, Section 211 (s.408) sets the schedule.
| Instalment | Due | Cumulative % of assessed tax |
|---|---|---|
| Q1 | 15 June | 15% |
| Q2 | 15 September | 45% |
| Q3 | 15 December | 75% |
| Q4 | 15 March | 100% |
The tolerance that is not what people think it is
The first proviso to Section 234C softens the first two instalments: pay at least 12% by the first date, or at least 36% by the second, and the interest for that instalment is waived entirely.
What it does not do is scale down. If you pay 11%, you miss the 12% gate, so the interest is not waived: you are charged 3% on the 4% gap between what you paid and the 15% due. Pay 12% and that instalment's interest disappears entirely. The proviso is a pass/fail gate, not a sliding scale. The third and fourth instalments have no tolerance at all.
Free · no loginEnter your assessed tax and what you paid by each date. The calculator shows the shortfall and interest per instalment, whether the 12% / 36% waiver applied, and the separate 234B charge — with the working shown.Where missing TDS makes this worse
Assessed tax is your tax for the year less the TDS deducted. So the advance tax you owed depended on how much your clients withheld — and if a deduction was made but never reported against your PAN, you cannot count it.
That produces a nasty compounding: the client keeps your money, you cannot claim the credit, your assessed tax is higher than you planned for, and you are charged interest for under-paying advance tax on a shortfall that was created by somebody else’s failure to file. If any of your deductions are missing, fix that first — here is why TDS goes missing and what actually recovers it.
How to avoid 234B and 234C next year
The interest is unavoidable once the dates have passed. Preventing it is genuinely straightforward, because the whole charge depends on one number you can estimate early:
- Work out assessed tax in the first quarter, not the last. Tax for the year less expected TDS. It does not need to be exact — it needs to be close enough to clear the thresholds in the table above.
- Check whether you are on one date or four. Presumptive filers under 44ADA pay once, by 15 March. Everyone else follows the ladder.
- Reconcile TDS quarterly, not annually. A deduction that is missing in July can still be corrected. The same deduction discovered in July of the following year is a much harder conversation and has already cost you interest.
That last point is where most of this interest actually originates. The overview of what a client’s TDS deduction means sets out when a deduction should appear and what to do about each of the ways it fails to.