Chartered Accountant · ICAI M.No. 153926 · FRN 136869W · Reviewed on 7 October 2026
How the dates interlock
The law fixes the audit report’s deadline relative to the return: one month before the section 139(1) due date. Audit-case returns are due 31 October, so Forms 3CA/3CB with 3CD are due 30 September. Where an international or specified domestic transaction brings section 92E in, the return moves to 30 November and the audit report to 31 October, with Form 3CEB alongside. The report is uploaded by the CA with a UDIN and then accepted by you in your e-filing login — unaccepted reports count as not filed.
If the date is missed
Section 271B: 0.5% of turnover, capped at ₹1,50,000 — unless reasonable cause is shown (courts have accepted auditor resignation, systems failure, serious illness). The report can and should still be filed late; penalty exposure is argued separately. Remember the collateral damage: a belated return also forfeits loss carry-forward under section 139(3), which often costs more than the penalty itself.
Working backwards from 30 September
A clean season runs: books closed and reconciled by July, balance confirmations and GST-vs-books reconciliation in August, draft 3CD by early September, signing with UDIN mid-month — never the last week, when the portal is at its slowest. FY 2025-26 is the final year under the Income-tax Act, 1961; from Tax Year 2026-27 the audit requirement continues under section 63 of the Income-tax Act, 2025. Our tax-audit practice runs this calendar for businesses and professionals.