Interest for filing the return after the due date, now section 423 of the 2025 Act
Estimates only, not financial advice. What you type stays on your device. Checked against sources on 30 Oct 2026.Interest under section 234A, now section 423 of the Income-tax Act, 2025, is 1% a month on the tax still unpaid when the return is filed after its due date. For FY 2026-27 the due date is 31 July 2027 for most people, 31 August for a business without audit and 31 October with audit. Filing on 20 August with ₹20,000 unpaid costs ₹200. The late filing fee is separate and not included.
₹2,150
Balance left to pay: ₹20,000.Income-tax Act, 2025 and Income-tax Rules, 2026, checked 30 Sep 2026. An estimate, not tax advice; the late filing fee is not included.
Tax paid on or before the due date is not charged. Courts read section 234A that way; section 423 does not say so in words.
FY 2026-27 · Rates and rules read from the sources listed on this page (the earliest on 30 Oct 2026); they may have changed since.
The page opens on the 234A working tab for interest on a late return.
Enter the Tax for the year and the advance tax you paid, so the tax unpaid on the due date is known.
Choose the Return due date (2027) that applies to you, then set Return filed on to your filing date.
Read the months counted after the due date and the 234A interest, also shown as 234A, late return in the result.
Enter the tax you expect to owe for FY 2026-27 after TDS and TCS, and what you have paid so far. The calculator shows how much was due by each date, where you fell short, and the interest the Income-tax Act, 2025 charges for it. It runs in your browser, is free, and nothing you type is sent anywhere.
It does not work out your tax; use the income tax calculator for that and bring the figure here. It does not apply the relief in section 425(4) for capital gains or dividends you could not foresee, it assumes the whole balance is paid on one day, and it leaves out the late filing fee. Figures and sections were checked on 30 September 2026.
The rest of the article, and all 6 questions about Advance Tax Calculator, are on the Advance Tax Calculator page.
Anyone whose tax for the year, after TDS and TCS, is ₹10,000 or more, under section 404 of the Income-tax Act, 2025. A resident aged 60 or more with no business or professional income is exempt under section 403(3). Salaried people usually owe none, because the employer deducts tax each month, unless they have large interest, rent or capital gains.
Take the amount due by the date, subtract what was paid by then, round down to a multiple of ₹100, and charge 3% for June, September and December or 1% for March. Under the Income-tax Act, 2025 this is section 425. With ₹10,000 paid against ₹15,000 due in June, the interest is 3% of ₹5,000, which is ₹150.
Interest under section 424, formerly 234B, applies when advance tax paid by 31 March is less than 90% of the tax for the year. It is 1% of the unpaid tax for each month or part of a month from 1 April until the balance is paid. Paying 90% or more by 31 March avoids it entirely.
No. The fee for filing after the due date is a separate charge under the Act and is not part of the interest shown here. Section 423 interest, formerly 234A, only runs on tax still unpaid, so paying the balance before the due date avoids it even if the return itself is filed late.
Rates and rules change; check the source before you rely on a figure.
Still stuck? Ask about Advance Tax Calculator and anybody who knows can answer. No account needed.
Same job, other tools: Marginal Relief Calculator – How marginal relief cuts the tax on income just above ₹12 lakh in the new regime · New Tax Regime Calculator – Tax under the default regime, including the rebate and marginal relief · TDS on FD for Senior Citizens – Whether a bank deducts TDS on a senior citizen’s FD interest under the ₹1 lakh limit.
On the related tools: GST Inclusive Calculator – Split a price that already includes GST into value and tax.
More for India: all 48 India calculators.