20 Sep 26 To add/amend particulars (other than GSTIN) in GSTR-1 of Aug. It can be filed after filing of GSTR-1 but before filing corresponding GSTR-3B.

20 Sep 26 Summary Return cum Payment of Tax for August by Monthly filers. (other than QRMP).

20 Sep 26 Monthly Return by persons outside India providing online information and data base access or retrieval services, for August.

25 Sep 26 Deposit of GST under QRMP scheme for August .

27 Sep 26 Filing of Financial Statements for FY 2025-26 by OPC Companies.

27 Sep 26 Submission of Cost Audit Report by Cost Auditor to the Board of Directors for FY 2025-26.

28 Sep 26 Return for August by persons with Unique Identification Number (UIN) like embassies etc to get refund under GST for goods and services purchased by them.

30 Sep 26 Transfer of unspent CSR amount to the CSR fund by All Companies whose CSR Expenditure is unspent as on 31st March and such amount is not marked for any ongoing project.

30 Sep 26 Quarter 2 – Board Meeting of All Companies

30 Sep 26 Annual General Meeting of All Companies.

30 Sep 26 KYC of All Directors (individuals) who hold DIN on 31st March, 2026.

30 Sep 26 Annual accounts along with the list of all principal places of business in India established by a foreign company (Branch / Liaison /Project Office)

30 Sep 26 Deposit of TDS on payment made u/s 393(1) [Table Sl. No. 2(i), 3(i), 6(ii) & 8(vi)] for purchase of property, payment of Rent more than 50,000 pm by individual or HUF (not liable to tax audit) where lease has terminated, certain other payments made by

30 Sep 26 Filing of Tax Audit Report where due date of ITR is 31 Oct.

30 Sep 26 Filing of MAT/AMT Audit Report etc. where due date of ITR is 31 Oct.

30 Sep 26 Filing of Audit Report u/s 80JJAA(2) for additional employment where due date of ITR is 31 Oct.

30 Sep 26 Filing of other Audit Reports , where due date of ITR is 31 Oct.

30 Sep 26 Application for exercising option under Explanation to section 11(1) to apply income of previous year in the next year or in future, if ITR due date is Nov 30.?

30 Sep 26 Filing of Statement to accumulate income for future application u/s 10(21) or 11(1), if ITR due date is Nov 30.?

30 Sep 26 Filing of Audit report by a fund or trust or institution or any university or other educational institution or any hospital or other medical institution?

30 Sep 26 Payment of membership fee for 2025-26 by ICAI Members.