§234A / 234B / 234C Interest Calculator

⚡ In shortSections 234A, 234B and 234C each charge 1% per month, but for three different failures — filing late, under-paying advance tax overall, and missing an individual instalment. Most notices combine two or three of them. 234A applies when you file the ITR after the due date: 1% per month on the tax still unpaid, from the day after the due date until you file. 234B applies when the advance tax you paid across the year is under 90% of your assessed tax: 1% per month on the shortfall, running from 1 April of the assessment year until it is paid. 234C penalises deferment of a specific instalment: the targets are 15%, 45%, 75% and 100% by 15 June, 15 September, 15 December and 15 March, and interest runs at 1% per month for three months on each of the first three shortfalls and one month on the last. Importantly 234C has a built-in tolerance — pay at least 12% by 15 June and 36% by 15 September and no interest arises on those instalments even though the targets are higher. Presumptive taxpayers under 44AD/44ADA sidestep 234C entirely by paying 100% by 15 March.

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How it is calculated

234A applies when you file the ITR after the due date: 1% per month on the tax still unpaid, from the day after the due date until you file. 234B applies when the advance tax you paid across the year is under 90% of your assessed tax: 1% per month on the shortfall, running from 1 April of the assessment year until it is paid. 234C penalises deferment of a specific instalment: the targets are 15%, 45%, 75% and 100% by 15 June, 15 September, 15 December and 15 March, and interest runs at 1% per month for three months on each of the first three shortfalls and one month on the last. Importantly 234C has a built-in tolerance — pay at least 12% by 15 June and 36% by 15 September and no interest arises on those instalments even though the targets are higher. Presumptive taxpayers under 44AD/44ADA sidestep 234C entirely by paying 100% by 15 March.

Frequently asked questions

What is the difference between 234B and 234C?

234B is about the year as a whole — it applies if your total advance tax is under 90% of the assessed tax. 234C is about timing — it applies if a particular instalment fell short of its 15/45/75/100% target, even if you paid everything by 15 March.

Can I avoid 234A by paying the tax but filing late?

Largely yes. 234A is charged on the tax that remains unpaid, so if you have already paid the tax through TDS or self-assessment, the 234A interest is nil or small — though the §234F late-filing fee still applies.

Is 234C really unavoidable if I earn irregularly?

Not always. The law relaxes 234C for income that could not be estimated in advance — such as capital gains or a lottery win — provided you pay the tax on it in the remaining instalments.

Is the interest calculated on full months?

Yes. Any part of a month counts as a whole month, so filing even one day into a new month adds another 1%.

Related reading

India Law Simplified is an AI-assisted tool, not a substitute for a licensed CA or advocate. Tax rules and limits change with each Finance Act — verify before relying on any figure.