Income Tax and GST Compliance Calendar of September 2026

Adhering to tax-related compliance proposed by the Indian government is mandatory for taxpayers in India. Such compliance also includes adhering to the due dates of GST return filing, about the complete compliance calendar detailed here and specified by the Indian government. Non-compliance with the due dates of GST return filing as per the June compliance calendar may result in the imposition of heavy penalties by the government on taxpayers in India. When it comes to tax evasion and corruption, tax compliance emerges as a central focus of the Indian government and the tax department.

In any case, a good citizen should always pay their taxes on time while adhering to all major tax-related rules and regulations proposed by the government, as it is vital for the upliftment of an economy. Paying taxes as per the compliance calendar by taxpayers also helps the government properly function the administrative work related to tax collection. Taxpayers can also avoid heavy penalties and fines imposed by the government by filing their Income Tax returns on time.

Here are some of the major due dates concerning various tax compliance by the September 2026 calendar:

September 2026 Compliance Calendar of Income Tax

Due Date	Description	Section
07-09-2026	“Due date for deposit of Tax deducted/collected for the month of August, 2026. However, all sum deducted/collected by an office of the government shall be paid to the credit of the Central Government on the same day where tax is paid without production of an Income-tax Challan”	TDS/TCS
07-09-2026	“Uploading of declarations received in Form No. 127 (Income-tax Rules, 2026) from the buyer in the month of August, 2026”	Form No. 127
14-09-2026	“Issue of certificate in Form No. 132 (Income-tax Rules, 2026) under section 395(4) of the Income-tax Act 2025 for tax deducted at source under section 393(1) [Table Sl. No. 2(i), 3(i), 6(ii) & 8(vi)] of the Income-tax Act, 2025 in the month of July, 2026.”	Form No. 132
15-09-2026	“Statement in Form 1 (Income-tax Rules, 2026) by the stock exchange for the month of August 2026, in respect of transactions in which client codes have been modified after registering in the system.”	Statement in Form 1
15-09-2026	“Due date for furnishing Form No. 137 (Income-tax Rules, 2026) by an office of the Government where TDS/TCS for the month of August, 2026 has been paid without the production of a challan”	Form No. 137
15-09-2026	“Second instalment of advance tax for the Tax Year 2026-27”	Advance Tax
30-09-2026	“Furnishing of audit report in Form no. 3CE (Income-tax Rules, 1962) under section 44DA (Income-tax Act, 1961) by a non-resident and foreign company for the previous year 2025-26 (if the assessee is required to submit return of income on October 31, 2026).”	Form no. 3CE
30-09-2026	“Furnishing of the report in Form No. 3CEA (Income-tax Rules, 1962) relating to computation of capital gains in case of slump sale taxable under section 50B (Income-tax Act, 1961) (if the assessee is required to submit return of income on October 31, 2026)”	Form No. 3CEA
30-09-2026	“Furnishing report under section 115JB (Income-tax Act, 1961) in Form No. 29B (Income-tax Rules, 1962) for computing the book profits of the company during the previous year 2025-26 (if the assessee is required to submit return of income on October 31, 2026”	Form No. 29B
30-09-2026	“Furnishing of the audit report in Form No. 10-IL (Income-tax Rules, 1962) by the specified fund, being the investment division of an offshore banking unit, for the purpose of exemption under section 10(4D) (Income-tax Act, 1961) (if assessee is required to submit return of income on or before October 31, 2026)”	Form No. 10-IL
30-09-2026	“Furnishing of certificate in Form No. 10-IJ (Income-tax Rules, 1962) issued by a Chartered Accountant certifying the annual statement of exempt income of the specified fund, being a category-III AIF, under section 10(23FF) (Income-tax Act, 1961) (if the assessee is required to submit the return of income on or before October 31, 2026)”	Form No. 10-IJ
30-09-2026	“Furnishing of Audit Report in Form No. 10CCB (Income-tax Rules, 1962) by assessee claiming deduction under section 80-I, 80-IA, 80-IB or section 80-IC (Income-tax Act, 1961) (if the assessee is required to submit the return of income on or before October 31, 2026)”	Form No. 10CCB
30-09-2026	“Furnishing audit report in Form No. 3AC (Income-tax Rules, 1962) by assessee claiming deduction under section 33AB (Income-tax Act, 1961) for the previous year 2025-26 (if the assessee is required to submit return of income on October 31, 2026)”	Form No. 3AC
30-09-2026	“Furnishing of report of audit of the accounts of an assessee, other than a company or a co-operative society, in Form No. 3AE (Income-tax Rules, 1962) under section 35D(4) (Income-tax Act, 1961) for the previous year 2025-26 (if the assessee is required to submit return of income on October 31, 2026)”	Form No. 3AE
30-09-2026	“Furnishing audit report in Form No. 3AD (Income-tax Rules, 1962) by assessee claiming deduction under section 33ABA (Income-tax Act, 1961) for the previous year 2025-26 (if the assessee is required to submit return of income on October 31, 2026)”	Form No. 3AD
30-09-2026	“Furnishing report in Form No. 10DA (Income-tax Rules, 1962) certifying the claim for additional employee cost under section 80JJAA (Income-tax Act, 1961) during the previous year 2025-26 (if the assessee is required to submit return of income on or before October 31, 2026)”	Form No. 10DA
30-09-2026	“Application in Form No. 171 (Income-tax Rules, 2026) for updating details by a person who is already registered as an income-tax practitioner under the Income-tax Act, 1961, holding a valid certificate of registration as on March 31, 2026”	Form No. 171
30-09-2026	“Furnishing of challan-cum-statement in Form No. 141 (Income-tax Rules, 2026) in respect of deduction of tax under section 393(1) [Table Sl. No. 2(i), 3(i), 6(ii) & 8(vi)] of the Income-tax Act, 2025 for the month of August 2026.”	Form No. 141
30-09-2026	“Furnishing of the report in Form No. 3CEA (Income-tax Rules, 1962) relating to computation of capital gains in case of slump sale taxable under section 50B (Income-tax Act, 1961) (if the assessee is required to submit return of income on October 31, 2026)”	Form No. 3CEA
30-09-2026	“Furnishing report under section 115JB (Income-tax Act, 1961) in Form No. 29B (Income-tax Rules, 1962) for computing the book profits of the company during the previous year 2025-26 (if the assessee is required to submit return of income on October 31, 2026)”	Form No. 29B
30-09-2026	“Furnishing report under section 115JC (Income-tax Act, 1961) in Form No. 29C (Income-tax Rules, 1962) for computing Adjusted Total Income and Alternate Minimum Tax of the person other than company during the previous year 2025-26 (if the assessee is required to submit return of income on October 31, 2026)”	Form No. 29C
30-09-2026	“Furnishing of Audit Report in Form No. 66 (Income-tax Rules, 1962) by tonnage tax company under clause (ii) of section 115VW (Income-tax Act, 1961) for the previous year 2025-26 (if the company is required to submit return of income on October 31, 2026)”	Form No. 66

Recommended: Income Tax Return Filing Due Dates

GST Compliance Calendar of September 2026

Due Dates	Compliance Particulars	Forms/(Filing Mode)
11.09.2026	The last date to file the GSTR-1 form is 11th September 2026, for taxpayers having an annual aggregate turnover of more than INR 1.5 crore or those who have opted for monthly return filing.	GSTR 1
13.09.2026	Monthly (August 2026)	IIF
20.09.2026	Annual Turnover of more than INR 5cr in the Previous FY | August 2026	GSTR 3B
20.09.2026	Annual Turnover of up to INR 5cr in the previous FY | August 2026	GSTR 3B
13.09.2026	All non-resident persons must file the GSTR-5 alongside the payment of GST on or before the given due date in August 2026.	GSTR 5
20.09.2026	All the non-resident ODIAR service providers should file their monthly return GSTR-5A on or before the given due date of 20th September 2026, for the month of August 2026.	GSTR 5A
13.09.2026	Every Input Service Distributor (ISD) must file GSTR-6 on or before the given due date of 13th September for the period of August 2026.	GSTR 6
10.09.2026	The due date for filing GSTR 7 for the period of August 2026 is 10th September.	GSTR-7
10.09.2026	The due date for furnishing GSTR 8 for the period August 2026 for registered e-commerce taxpayers in India who are liable to pay TCS should be deducted on or before deducted on or before 10th September.	GSTR 8