GSTR-1 & GSTR-3B Due Dates August 2026: Late Fee & Interest Calculator
GSTR-1 for July 2026 is due by 11 August (monthly) and GSTR-3B by 20 August 2026. Know quarterly QRMP dates and what late filing costs you.
GST Return (3B and R1)
Combined GSTR-3B and GSTR-1 return filing at ₹1,800. Complete monthly GST return solution by GSTC INDIA GROUP.
GST NIL Return Filing
File your GST NIL return at just ₹738. Perfect for businesses with no sales or purchases in a tax period. Hassle-free, paperless filing.
Due dates for July 2026 returns
- GSTR-1 (July 2026, monthly): 11 August 2026 (10th for some states; many states use the 11th for B2B via IFF-based normal filing)
- GSTR-1 (quarterly QRMP, Apr-Jun 2026 anyway passed - Q1 deadline was 13 July 2026): next is Q2 Jul-Sep, due 13 October 2026
- GSTR-3B (July 2026, monthly): 20 August 2026
- GSTR-3B (quarterly QRMP Q2): 22/24 October 2026 by state
- PMT-06 monthly tax payment: 25th of each month for first two months of the quarter
Late fee structure
- Monthly returns: Rs. 50 per day (Rs. 25 CGST + Rs. 25 SGST), nil returns Rs. 20 per day
- Caps: turnover up to Rs. 1.5 crore - Rs. 2,000; Rs. 1.5-5 crore - Rs. 5,000; above Rs. 5 crore - Rs. 10,000
- Interest: 18% per annum on unpaid tax liability
- Inter-state (IGST default) similar Rs. 50/day
Effective from
Standard monthly cycle for August 2026 filing season: GSTR-1 by 11th, GSTR-3B by 20th, no extension notifications have been issued for July 2026 returns as of publication.
Impact on businesses
Missed filings block ITC for buyers - your recipient sees the supplier's invoice only after GSTR-1 is filed. Late filing also blocks opting into QRMP, new registrations, refunds and other services on the GST portal.
What you should do
- Reconcile sales and purchases daily so data is ready a week before the due date
- Verify GSTR-2B for July against purchase registers to catch missing supplier invoices
- Set calendar alerts for the 11th, 20th and 25th
- If you missed June 2026, file immediately with the late fee - do not let interest compound
Need help filing this? Our advisors handle it end-to-end
GST Return (3B and R1)
Combined GSTR-3B and GSTR-1 return filing at ₹1,800. Complete monthly GST return solution by GSTC INDIA GROUP.
GST NIL Return Filing
File your GST NIL return at just ₹738. Perfect for businesses with no sales or purchases in a tax period. Hassle-free, paperless filing.