Tax Compliance Tracker: Sep 2023

September is the densest compliance month in India. Key deadlines include 7 September for TDS deposit, 15 September for the second advance tax instalment (45%) and PF/ESI, 20 September for GSTR-3B, 27 September for AOC-4 filing, and 30 September for tax audit report, DIR-3 KYC, and the cut-off for ITC claims and credit notes relating to FY 2025-26 under Sections 16(4) and 34(2). Missing these triggers ₹100-per-day MCA penalty, 1% per month TDS interest, and ITC denial.

Mayank Wadhera

Published: 1 Sept 2023

Updated: 16 May 2026

4 min read

September is the most compliance-heavy month of the Indian financial year. For FY 2026-27, the September compliance calendar packs together income tax audit, ITR for audited taxpayers, GST annual return prep, TDS challans, and DIR-3 KYC. A single missed deadline can trigger ₹100-per-day MCA penalties, 1% per month TDS interest, and audit-report delays that cascade into October.

Direct tax: the heaviest September

7 September: Deposit of TDS and TCS for August
14 September: Issue of TDS certificates for July (non-salary) under Form 16A, 16B, 16C, 16D
15 September: Advance Tax — second instalment, 45% of estimated annual tax for individuals and corporates not opting for presumptive scheme
30 September: Tax audit report (Form 3CA/3CB and 3CD) for FY 2025-26 (AY 2026-27)
30 September: ITR for assessees subject to audit (where no transfer pricing) — verify whether the deadline applies in your case

Indirect tax (GST) deadlines

10 September: GSTR-7 (TDS under GST) and GSTR-8 (TCS by e-commerce operators) for August
11 September: GSTR-1 for August (monthly filers)
13 September: GSTR-1 QRMP IFF for August
20 September: GSTR-3B for August (monthly filers)
25 September: PMT-06 challan for QRMP taxpayers (August)
30 September: Last date for amendment, ITC claim and credit note related to FY 2025-26 (per Section 16(4) and Section 34(2))

MCA and corporate compliance

27 September: AOC-4 filing for FY 2025-26 (180 days from financial year end)
30 September: DIR-3 KYC for every director with active DIN as on 31 March 2026
30 September: Annual General Meeting for companies other than OPC and one-person LLPs

PF, ESI and labour

15 September: PF and ESI contribution and return for August
15 September: Professional Tax payment (varies by state)
Verify state-specific shop and establishment renewal dates
Track LWF (Labour Welfare Fund) half-yearly cycles in applicable states

Why September matters strategically

September is the bridge between the prior FY closing audit and the current FY first half. Files closed cleanly here set up cleaner GST annual return work in November-December and smoother corporate annual filings through October. A clear war room for the month — a single dashboard tracking each statutory deadline — is the single most useful internal tool a CFO can deploy.

Building an internal September war room

Treat September as a project with clear ownership. Designate one accountable owner per workstream — direct tax (audit, ITR, advance tax), indirect tax (GST returns, ITC reconciliation), corporate (AOC-4, DIR-3 KYC, AGM), and payroll (PF, ESI, professional tax). Hold a kick-off meeting in late August to lock down the calendar, identify dependencies, and pre-empt potential blockers like missing vendor invoices or pending bank confirmations. From mid-September, run a daily 15-minute standup to track progress and escalate exceptions. Use a shared dashboard — Excel, Notion, or a dedicated compliance tool — to make status visible. The cost of one missed deadline (₹100 per day MCA penalty, 1% per month TDS interest, ITC reversal under Rule 37A) almost always exceeds the cost of war-room discipline.

Common errors that cost businesses in September

Specific September errors recur every year. Filing tax audit reports with incorrect Form 3CD clauses, particularly Clause 21 on cash payments and Clause 34 on TDS; mismatched figures between books and GSTR-9 leading to demand notices; missed advance tax payment leading to interest under Section 234B and 234C; DIR-3 KYC not refreshed because the director assumed it was a one-time exercise; AOC-4 filed with incorrect XBRL classification. Each of these is preventable with a 15-minute pre-flight check before submission. Maintain a September close checklist that includes peer review of every major filing — a second pair of eyes typically catches the issues that the preparer's familiarity misses.

For multi-state businesses, layer the central September calendar with state-specific deadlines — professional tax in Maharashtra, Karnataka, West Bengal; state-level shop and establishment renewals; and state EPF and ESI nuances where applicable. A single missed state deadline can disrupt a clean central compliance picture. Maintain a state-by-state compliance matrix updated quarterly, and assign a regional owner for each cluster of states to ensure that no jurisdiction-specific deadline gets missed amid the volume of central deadlines.

Conclusion

Treat September 2026 as a project, not a checklist. Map every deadline two weeks in advance, assign owners, and have a daily standup for the last ten days. With tax audit, ITR, MCA AOC-4, GST September cut-off and DIR-3 KYC all converging, even one missed item creates a domino effect. Discipline in September is the single highest-ROI compliance investment of the year.

Frequently Asked Questions

What is the tax audit due date for FY 2025-26?

The tax audit report under Section 44AB for FY 2025-26 (Assessment Year 2026-27) is generally due by 30 September 2026. The deadline applies to taxpayers whose turnover exceeds ₹1 crore (or ₹10 crore where digital transactions are 95% or more), or professionals with gross receipts above ₹50 lakh, or those covered under presumptive provisions in specified situations.

When is the second advance tax instalment due?

The second advance tax instalment is due by 15 September each year, with a cumulative payment of 45% of the estimated annual tax liability. This applies to individuals, HUFs, firms and companies not opting for the Section 44AD or 44ADA presumptive schemes. Shortfall attracts interest under Sections 234B and 234C.

What is the DIR-3 KYC deadline?

Every individual holding a Director Identification Number (DIN) as on 31 March of a financial year must complete DIR-3 KYC by 30 September of the following financial year. Failure to file results in the DIN being marked Deactivated, blocking all MCA filings, and reactivation requires a fee of ₹5,000.

Why is 30 September important for GST?

Under Section 16(4), the last date to claim ITC for invoices relating to the previous financial year, and under Section 34(2), the last date to issue credit notes for that year, is 30 November of the following financial year. However, September is the practical operational cut-off for FY-end ITC matching and credit note review.