Most business owners remember monthly GST returns and salary-related TDS. The deadlines most likely to be missed, however, are often the annual or transaction-specific filings handled outside the regular monthly compliance cycle.
Between September 22 and December 31, 2026, businesses may face important obligations relating to tax audits, income-tax returns, transfer pricing, advance tax and GST annual reconciliation.
Not every deadline applies to every business. Applicability depends on turnover, entity type, transactions, audit requirements and filing history. This checklist reflects the ordinary statutory position as of September 22, 2026; businesses should still monitor official notifications for extensions or procedural changes.
1. September 30: Tax Audit Report for Non-Transfer-Pricing Cases
Businesses and professionals covered by the tax-audit provisions for FY 2025-26 ordinarily need to obtain and furnish their audit report by September 30, 2026, where the related income-tax return is due on October 31.
The report is generally filed in Form 3CA or Form 3CB with the particulars prescribed in Form 3CD, as applicable.
The Income Tax Department has clarified that the FY 2025-26 tax audit remains governed by the Income-tax Act, 1961, even though the filing occurs after the new Income Tax Act came into force.
Checklist:
- Finalise books and financial statements
- Reconcile turnover with GST returns
- Review TDS compliance and expense disallowances
- Confirm loans, deposits and cash transactions
- Upload and accept the audit report before the deadline
An audit report uploaded by the auditor may still require acceptance through the taxpayer’s e-filing account.
2. October 31: Income-Tax Return for Audit Cases
Taxpayers whose accounts are required to be audited generally have an income-tax return deadline of October 31, 2026, unless they fall within the separate transfer-pricing category.
This may include companies, firms, LLPs, proprietorships and professionals subject to audit, depending on the applicable provisions.
Filing the tax audit report does not complete the income-tax return obligation. The return must separately report taxable income, deductions, losses, depreciation, tax credits and other prescribed information.
Checklist:
- Match the return with the audited financial statements
- Reconcile Form 26AS and the Annual Information Statement
- Verify brought-forward losses and depreciation
- Confirm TDS, TCS and advance-tax credits
- Complete digital verification after submission
Late filing may result in fees, interest and restrictions on carrying forward certain losses.
3. October 31: Transfer-Pricing Report for Specified Transactions
Businesses entering into international transactions or specified domestic transactions may need to obtain and furnish the accountant’s report in Form 3CEB by October 31, 2026.
This deadline is separate from the November 30 income-tax return deadline applicable to transfer-pricing cases. The Income Tax Department confirms that October 31 is the audit-report deadline where the corresponding return is due on November 30.
Transfer-pricing compliance may apply to transactions involving:
- Overseas parent or subsidiary companies
- Cross-border management or support services
- Intercompany loans and guarantees
- Royalties and software charges
- Imports or exports between associated enterprises
- Certain specified domestic arrangements
Businesses should not wait until October to prepare benchmarking studies and intercompany documentation.
4. November 30: Income-Tax Return for Transfer-Pricing Cases
A taxpayer required to submit a transfer-pricing report ordinarily has until November 30, 2026 to file the income-tax return for FY 2025-26.
Form 3CEB and the income-tax return must tell a consistent story. Differences in transaction values, associated-enterprise details or transfer-pricing adjustments may attract questions during assessment.
Checklist:
- Reconcile Form 3CEB with the general ledger
- Verify foreign-currency conversion
- Review transfer-pricing adjustments
- Match related-party disclosures with financial statements
- Confirm foreign tax credits and withholding documents
Businesses should also ensure that agreements, invoices and actual conduct support the pricing policy reported in the return.
5. December 15: Third Advance-Tax Instalment
The third advance-tax instalment for the current tax year is ordinarily due on December 15, 2026.
Advance tax generally becomes relevant where the estimated tax liability, after considering eligible tax credits, crosses the prescribed threshold. The Income Tax Department explains that taxpayers with annual tax payable exceeding ₹10,000 generally need to pay advance tax through quarterly instalments.
By December 15, most taxpayers are expected to have paid the prescribed cumulative proportion of their annual advance-tax liability.
Businesses should update projections for:
- Profit earned through November
- Expected year-end sales and expenses
- Capital gains
- Interest and rental income
- TDS and TCS credits
- Earlier advance-tax payments
Underestimation can result in interest even where the final return is filed on time.
6. December 31: Belated Return for AY 2026-27
A taxpayer who missed the original income-tax return deadline for FY 2025-26 may generally file a belated return by December 31, 2026, or before completion of assessment, whichever is earlier.
The Income Tax Department confirms this deadline for Assessment Year 2026-27 and notes that late-filing fees may apply.
A belated return should not be treated as a normal extension. Consequences may include:
- Late-filing fees
- Interest on unpaid tax
- Loss of certain carry-forward benefits
- Delayed refunds
- Greater difficulty correcting records near the deadline
Businesses should complete the filing early enough to resolve mismatches in tax credits or portal data.
7. December 31: GSTR-9 and GSTR-9C for FY 2025-26
Eligible GST-registered businesses must ordinarily file their annual return in Form GSTR-9 by December 31, 2026.
Taxpayers crossing the prescribed turnover threshold may also need to submit the self-certified reconciliation statement in Form GSTR-9C. Rule 80 provides relief from GSTR-9C up to the applicable turnover threshold, currently referenced as ₹5 crore.
Before filing, businesses should reconcile:
- GSTR-1 with GSTR-3B
- Turnover with audited financial statements
- Input tax credit with purchase records and GSTR-2B
- Credit notes and debit notes
- Reverse-charge liabilities
- Exempt, nil-rated and non-GST supplies
Annual-return filing should be treated as a final GST control exercise—not a mechanical consolidation of monthly figures.
The December Compliance Plan
Business owners should assign every deadline to a responsible person and maintain a shared tracker containing:
- Applicability
- Form and reporting period
- Internal data-cut-off date
- Reviewer and approver
- Filing status
- Payment reference
- Acknowledgement number
Internal deadlines should be placed at least seven to ten days before the statutory date.
Shunyatax Global Insights
The final quarter is where income-tax, transfer-pricing and GST obligations begin to overlap. One unreconciled number can affect several filings.
Businesses should complete a combined review of books, GST returns, TDS records, related-party transactions and tax payments instead of handling each deadline independently.
If your business needs assistance with tax audits, income-tax returns, transfer pricing, advance tax, GSTR-9 or GSTR-9C, Shunyatax Global can provide professional guidance to help you meet the applicable deadlines with clarity and confidence.
Contact Shunyatax Global
Phone: +91 94615 14198
Email: office@shunyatax.in
Website: www.shunyatax.in
Disclaimer: The deadlines listed reflect the ordinary statutory position as of September 22, 2026. Applicability varies according to the taxpayer’s facts, and the Government may extend or modify deadlines through notifications. This content is for general information and does not constitute legal, tax or financial advice.