Free calculator

Interest Calculator — Sections 234A, 234B & 234C

Interest for late return and advance-tax shortfall. Free, no sign-up — the maths runs in your browser.

Interest Sections 423, 424 & 425 of the 2025 Act Old & new sections

Interest payable—

Tax after TDS—

234A — late return—

234B — advance-tax default—

234C — deferment—

Estimate for planning — not a final computation. Rates as per Budget 2026, GST 2.0 and the Income-tax Act, 2025.

How this calculator works

Computes simple interest at 1% per month: 234A for a late return, 234B when advance tax paid is below 90% of tax due, and 234C for each instalment that fell short (with the 12% and 36% safe harbours). Shortfalls are rounded down to the nearest ₹100 as the rules require.

Worked example

Tax ₹2 lakh, TDS ₹50,000, entire ₹1.5 lakh paid as advance tax only in March: 234C ≈ ₹6,075; no 234B because 90% was paid by 31 March.

How to read section numbers: s.80C→s.123 means Section 80C of the Income-tax Act, 1961 is now Section 123 of the Income-tax Act, 2025 (in force from 1 April 2026). Returns for FY 2025-26 still use the old numbers; Tax Year 2026-27 onwards uses the new ones. Section Finder

FAQ

Questions about this calculator

Yes, for all three sections.

234B and 234A run up to the date of payment/filing; this calculator assumes tax is paid on the filing date.

Only in limited cases by senior officers under CBDT orders; usually it is mandatory.

Tax Library

Understand the law behind this calculator

Section 139 → 263: Filing your return — original, belated, revised, updatedSection guide Section 156 → 289: Notice of demand — pay, dispute or staySection guide Section 234A, 234B, 234C → 423, 424, 425: Interest for late return & advance-tax defaultSection guide Section 208, 211 → 404, 408: Advance tax — who pays and whenSection guide ITR-3ITR form ITR-5 (firms, LLPs)ITR form

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