GSTR-3B Filing Guide 2026 — Summary Return Made Simple

GSTR-3B is where you actually pay tax. In my practice, I have seen businesses pay 50,000+ in unnecessary late fees because they misunderstood this return.

GSTR-3B is a simplified summary return where taxpayers declare their GST liability, claim Input Tax Credit, and pay the net tax. It must be filed monthly by the 20th of the following month.

What is GSTR-3B?

Unlike GSTR-1 which reports transaction-level data, GSTR-3B is a self-declared summary return. It captures total outward supply, inward supply (ITC), and the net tax payable. It is a provisional return that gets reconciled with GSTR-1 data.

Key Tables

• Table 3.1: Outward supplies and inter-state supplies
• Table 3.2: Of the supplies in 3.1, details of inter-state supplies to unregistered persons
• Table 4: Eligible ITC — split into CGST, SGST, IGST
• Table 5: Exempt, nil-rated, and non-GST supplies
• Table 6: Payment of tax — tax paid through ITC and in cash

ITC Rules to Know

• ITC can only be claimed if the supplier has filed their GSTR-1 (matching with GSTR-2A)
• Blocked ITC under Section 17(5) — motor vehicles, food, travel, cosmetics, etc.
• ITC must be reversed for exempt supplies proportionately
• Time limit: ITC must be claimed by the due date of September return of the following year or annual return, whichever is earlier

How to File GSTR-3B

1. Login to gst.gov.in → Services → Returns → Returns Dashboard
2. Select the return period and click "Prepare Online"
3. Fill in outward supply details in Table 3
4. Enter eligible ITC in Table 4
5. System calculates net tax liability
6. Create challan for cash payment (if needed)
7. Check the cash/ITC ledger balance
8. File using DSC or EVC

Important: Always check your ITC eligibility through GSTR-2A/2B matching before claiming. Wrong ITC claims can attract interest, penalty, and even prosecution.