GST Return Filing Made Simple: GSTR-1, GSTR-3B, Due Dates and Late Fees

Getting a GSTIN is only the beginning. Every registered business has to file GST returns on time — even when there are no sales. Missed returns lead to late fees, interest, blocked e-way bills and, in serious cases, cancellation of registration. Here is a plain-language guide to the returns most small businesses file.

The main GST returns

• GSTR-1: Details of your outward supplies (sales invoices, credit/debit notes).
• GSTR-3B: Summary return where you declare tax liability, claim input tax credit and pay tax.
• GSTR-9: Annual return for the financial year (GSTR-9C reconciliation applies to larger businesses).
• CMP-08 and GSTR-4: Quarterly statement and annual return for businesses under the Composition Scheme.

Monthly vs quarterly (QRMP) filing

Businesses with turnover up to ₹5 crore can opt for the QRMP scheme — returns are filed quarterly while tax is paid monthly.

• Monthly filers: GSTR-1 by the 11th and GSTR-3B by the 20th of the following month.
• QRMP filers: GSTR-1 by the 13th of the month after the quarter (B2B invoices can be uploaded monthly through IFF), and GSTR-3B by the 22nd or 24th depending on your state. Tax for the first two months is paid by the 25th using PMT-06.
• Annual return (GSTR-9): generally due by 31 December after the financial year.

Due dates are sometimes extended by notification, so always check the current calendar on the GST portal.

Late fees and interest

• Late fee: ₹50 per day (₹25 CGST + ₹25 SGST) for GSTR-3B and GSTR-1, and ₹20 per day for nil returns, subject to caps linked to turnover.
• Interest: 18% per year on tax paid late, generally on the net cash liability.
• Other consequences: blocked e-way bills, buyers losing input tax credit and possible cancellation of registration for continued non-filing.

Recent changes to keep in mind

• Tax liability auto-filled in GSTR-3B from your GSTR-1 is now locked, so mistakes must be corrected through GSTR-1A or the next GSTR-1 before you file GSTR-3B.
• Returns can no longer be filed once three years have passed from the original due date, so old pending returns should be cleared as early as possible.

5 habits for stress-free GST compliance

1. Issue proper GST invoices with correct GSTIN, HSN/SAC and place of supply.
2. Reconcile purchases with GSTR-2B every month before claiming input tax credit.
3. Make sure your suppliers file their GSTR-1 on time — your credit depends on it.
4. File nil returns even in months with no business.
5. Keep a single compliance calendar — or hand it over to a team that tracks due dates for you.

Not registered yet? Start with our guide to GST registration.

Related reads

• GST Registration: who needs it and how to apply
• ITR Filing Guide: forms, documents and deadlines
• Private Limited Company Registration: process and timeline

This article is general information, not legal or tax advice. Rules, limits and due dates change through notifications, so confirm the current position before you act, or simply ask us.