GSTMarch 11, 2026 • Taxation Specialist
How to File GSTR-1 and GSTR-3B Returns: A Step-by-Step Guide (2026)
Filing Goods and Services Tax (GST) returns is a crucial practical skill for every chartered accountant and business owner in India. The two primary monthly returns that every regular taxpayer must file are GSTR-1 and GSTR-3B.
Here is a simplified, compliance-ready step-by-step roadmap to filing these returns without errors.
Phase 1: Filing GSTR-1 (Outward Supplies) 📦
GSTR-1 contains details of all your sales and outward supplies. It must be filed by the 11th of the succeeding month (or 13th for QRMP scheme taxpayers).
Steps to file GSTR-1:
- Log in: Access the GST Common Portal (gst.gov.in) with secure credentials.
- Add Invoices: Populate B2B invoices in Table 4A, B2C Large in Table 5, and B2C Small in Table 7. Ensure invoice numbers, HSN codes, and tax rates match your ERP or billing records.
- HSN Summary: Enter HSN-wise summary of outward supplies in Table 12. Errors here attract warning triggers.
- Generate Summary & Verify: Generate the GSTR-1 summary, preview draft, and verify using Electronic Verification Code (EVC) or Digital Signature Certificate (DSC).
Phase 2: Filing GSTR-3B (Summary of Tax & Payment) 💳
GSTR-3B is a monthly self-declaration return containing summarized figures of outward supplies, input tax credit (ITC) claimed, and taxes paid. It is filed by the 20th of the succeeding month.
Steps to file GSTR-3B:
- Verify Auto-populated Fields: Check Table 3.1 (Outward supplies) and Table 4 (Eligible ITC) which are auto-populated from GSTR-1 and GSTR-2B respectively.
- ITC Reconciliation: Perform a strict match between your purchase register and the auto-populated GSTR-2B. Reclaim any matching ITC and reverse ineligible/blocked credit under Section 17(5).
- Taxes Payment & Offset: Offset your output liability using the available cash/credit ledger balances. If credit is insufficient, generate a Challan and pay the remaining balance online.
- File: Complete the filing process using DSC or EVC.