GSTR-3B is the return where you actually pay your GST. Miss it and interest starts running at 18% per year. Here's the plain-English process.
What is GSTR-3B?
GSTR-3B is a monthly self-declared summary return showing your total sales, input tax credit (ITC) claimed, and net tax paid. Unlike GSTR-1 (invoice-level detail), GSTR-3B is totals only — but the two must match, because the GST portal compares them.
When is GSTR-3B due?
For monthly filers, the 20th of the following month. QRMP scheme taxpayers pay monthly via PMT-06 and file GSTR-3B quarterly (22nd or 24th depending on state). Filing after the due date attracts a late fee of ₹50 per day (₹20 for nil returns) plus 18% annual interest on unpaid tax.
Step-by-step filing
- Reconcile the month's sales and purchases first — your GSTR-3B totals must match GSTR-1.
- Log in to gst.gov.in → Returns Dashboard → select the period → GSTR-3B.
- Fill Table 3.1 (outward supplies) with your total taxable value and tax.
- Fill Table 4 (eligible ITC) — claim only credit backed by supplier-filed invoices visible in GSTR-2B.
- Offset liability using ITC first, pay the balance in cash via challan.
- File with DSC or EVC and download the acknowledgement.
The most common GSTR-3B mistakes
- Claiming ITC that doesn't appear in GSTR-2B — this triggers notices.
- GSTR-1 and GSTR-3B totals not matching — the portal flags the difference.
- Forgetting reverse-charge liability on services like transport (GTA) or legal fees.
- Paying the tax but forgetting to actually file the return — the late fee still applies.
Make it painless
BizGST Pro keeps a running summary of your outward supplies and sends you a reminder before the 20th every month, so your GSTR-3B numbers are ready before you log in to the portal.