GSTR-3B
What GSTR-3B means, how it works, a worked example, the mistakes we see and the questions founders ask.
DefinitionGSTR-3B is the monthly self-assessed summary GST return in which a business declares its total sales, claims input tax credit and pays the net tax, due by the 20th of the following month.
GSTR-3B is where GST is actually paid. It summarises outward supplies, reverse charge liabilities and eligible input tax credit, and the difference is settled from the electronic cash ledger before filing. Monthly filers submit by the 20th; QRMP filers pay tax monthly by the 25th through a challan and file the return quarterly by the 22nd or 24th depending on the state. The input credit you claim should match GSTR-2B, the auto-drafted statement built from your suppliers' GSTR-1 filings. You meet it every month, and it is the return most often filed late. What it means for you: late filing costs ₹50 per day (₹20 for nil returns) with caps, plus 18% interest on tax paid late, and two consecutive unfiled returns block e-way bill generation.
How GSTR-3B works
GSTR-3B is where the tax is actually paid. It summarises outward supplies by type, the input tax credit claimed, the net tax payable under CGST, SGST, IGST and cess, and is filed with payment by the 20th of the following month, or for QRMP filers by the 22nd or 24th of the month after the quarter depending on the State, with tax paid monthly through PMT-06.
The outward figures are auto-drafted from GSTR-1 and the credit from GSTR-2B, the static statement of what your suppliers reported. Claiming credit that is not in 2B is now blocked by rule, so a supplier who files late delays your credit to the month they file. Interest at 18% a year runs from the due date on tax paid late, and the late fee is ₹50 a day (₹20 nil) with turnover caps.
GSTR-3B became final rather than editable from July 2025: the auto-populated figures can be corrected only through GSTR-1A before filing, not by overwriting them in 3B. That makes the GSTR-1 to GSTR-1A step the place where the month's numbers get settled.
A Delhi distributor's GSTR-1 for August shows ₹60 lakh of sales and ₹10.8 lakh of output tax. Its GSTR-2B shows ₹8.2 lakh of credit from suppliers who filed on time; one supplier's ₹40,000 of credit is missing because he filed late. The distributor pays ₹2.6 lakh net on 18 September and claims the missing ₹40,000 in October when it appears in that month's 2B.
Mistakes we see with GSTR-3B
- Claiming credit from the purchase register instead of GSTR-2B, which the portal flags and the officer reverses with interest.
- Paying the tax on the 20th but filing the return on the 25th; the late fee runs on the return, not the payment.
- Reporting interstate sales under CGST and SGST (or the reverse); the wrong head cannot simply be adjusted and needs a refund and repayment.
Last updated 19 October 2026. Checked against the MCA, GST, Income-tax and Trade Marks rules in force for October 2026.
Where you will meet this term
Questions founders ask about GSTR-3B
What is the due date for GSTR-3B?
The 20th of the next month for monthly filers. QRMP filers file quarterly by the 22nd (southern and western States) or 24th (the rest) of the month after the quarter, paying tax monthly by the 25th through PMT-06.
What if my supplier has not filed GSTR-1?
The credit will not be in your GSTR-2B and cannot be claimed that month. It appears in the 2B of the month your supplier files, and you claim it then, as long as it is before 30 November of the following year.
What is the interest on late GST payment?
18% a year on the net tax paid late, counted from the due date to the date of payment, plus the late fee on the return. Credit wrongly claimed and reversed also carries 18% interest since the 2022 amendment.