GST Due Dates in September 2025

GST Due Dates in September 2025: Complete Filing Calendar for Taxpayers

September 2025 presents a busy month for GST compliance with multiple return filing deadlines across various forms. As we move deeper into FY 2025-26, businesses need to stay vigilant about their GST obligations to avoid penalties and interest charges. Here's a comprehensive breakdown of all GST due dates for September 2025.

Key GST Filing Deadlines in September 2025

September 10, 2025

GSTR-7 and GSTR-8 Returns

• GSTR-7: TDS (Tax Deducted at Source) return for August 2025
• GSTR-8: TCS (Tax Collected at Source) return for e-commerce operators for August 2025

These forms must be filed by businesses that deduct or collect tax at source under the GST regime.
Also Read: Latest Income Tax Notifications 2025: Key Updates Every Taxpayer Should Know

September 11, 2025

GSTR-1 Return - Monthly Filers

• GSTR-1: Outward supplies return for August 2025
• Applicable to taxpayers with annual turnover exceeding ₹1.5 crores or those who have opted for monthly filing

September 13, 2025

Multiple Return Forms

• GSTR-5: Return for non-resident taxable persons for August 2025
• GSTR-6: Input Service Distributor (ISD) return for August 2025
• IFF (Invoice Furnishing Facility): Optional monthly filing for August 2025

September 20, 2025

GSTR-3B Returns - Most Critical Deadline

• GSTR-3B: Summary return for August 2025
• Applicable to all monthly filers regardless of turnover
• GSTR-5A: Return for OIDAR (Online Information and Database Access or Retrieval) service providers for August 2025

Also Read: FEMA Act Case Study 3: Cross-Border Investment Gone Wrong

September 25, 2025

PMT-06 Form

• PMT-06: Monthly payment under QRMP (Quarterly Return Monthly Payment) scheme for August 2025
• Applicable only if not covered in quarterly GSTR-3B filing

Also Read: GST 2.0: India’s Two-Slab Tax Revolution Begins 22 September 2025

Important Notes for September 2025 Compliance

Quarterly Filers Exception

For businesses under the QRMP scheme with turnover up to ₹5 crores, the quarterly GSTR-3B for July-September 2025 quarter will be due on October 22, 2025 (Category X states) or October 24, 2025 (Category Y states/UTs).

Annual Returns Reminder

GSTR-9 and GSTR-9C for FY 2024-25 are due on December 31, 2025. While not due in September, taxpayers should begin preparation early.

Composition Scheme Dealers

The next CMP-08 quarterly challan for composition taxpayers covering July-September 2025 will be due on October 18, 2025.

Penalty and Interest Implications

Late filing of GST returns attracts:

• Late fees of ₹50 per day per return (₹25 under CGST + ₹25 under SGST)
• Interest at 18% per annum on outstanding tax liability
• Potential suspension of GST registration for continuous defaults

Best Practices for September 2025 Compliance

1. Mark Calendar Dates: Set reminders for all applicable due dates based on your business type
2. Early Preparation: Don't wait until the last moment, especially for GSTR-3B on September 20th
3. Regular Reconciliation: Ensure purchase and sales data is reconciled before filing
4. Technical Backup: File at least 2-3 days before due dates to avoid technical glitches
5. Professional Assistance: Consider engaging tax professionals for complex cases

September 2025 requires careful attention to GST compliance timelines. With multiple forms due throughout the month, businesses should establish a systematic approach to ensure all obligations are met on time. The most critical date remains September 20, 2025, for GSTR-3B filing, which affects the majority of GST-registered taxpayers.