How do I file GSTR-3B?

By the India Law Simplified editorial team · Verified against the bare Acts & official portals · Updated 2026-08-18 · ~8 min read

⚡ Quick answer

GSTR-3B is the summary GST return where you declare your total sales, claim input tax credit, and pay the net tax. To file it: log in to the GST portal, select the return period, enter your outward supplies and tax in Table 3.1, claim eligible ITC (matched to GSTR-2B) in Table 4, set off the liability against ITC and cash, and file with DSC or EVC. Monthly filers' due date is the 20th of the following month; quarterly (QRMP) filers file by the 22nd or 24th.

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GSTR-3B is the monthly (or quarterly) heartbeat of GST compliance — it's where you actually declare your tax and pay it. Filing it correctly and on time keeps your registration active and protects your buyers' input tax credit. This guide gives you the exact step-by-step process on the GST portal, the due dates, how late fees and interest are calculated, and the most common mistakes that cause notices.

1What GSTR-3B is

GSTR-3B is a self-declared summary return. Unlike GSTR-1 (which lists every invoice), GSTR-3B just declares your totals: total outward supplies and tax, total ITC claimed, and the net GST you pay. Every regular taxpayer files it, even for a month with no business (a 'nil' return).

⚠️ ImportantGSTR-3B and GSTR-1 are separate returns and both must be filed. GSTR-1 (your sales invoices) feeds into your buyers' GSTR-2B, so filing it late hurts your customers' ITC.

2Before you file: reconcile

The single most important step happens before you touch the portal — reconcile your books with GSTR-2B. Match the ITC you intend to claim against what appears in GSTR-2B, because you can only claim credit that's reflected there. Also total your sales correctly.

3Step by step on the GST portal

Once your figures are ready:

Log in to gst.gov.in and go to Returns Dashboard → select the financial year and return period.
Open GSTR-3B and fill Table 3.1 — outward supplies and the tax on them (and any reverse-charge liability).
Fill Table 4 — eligible ITC, after matching to GSTR-2B and reversing any blocked/ineligible credit.
The portal computes your net liability; pay any balance in cash by creating a challan (PMT-06).
Offset the liability against ITC and cash, then submit and file using DSC or EVC (OTP).

✅ TipAlways file even a NIL return on time. A skipped return blocks your next return (returns must be filed in sequence) and stops you from filing GSTR-1 too.

4Due dates

The due date depends on whether you file monthly or under the QRMP (Quarterly Return Monthly Payment) scheme:

Monthly filers: 20th of the following month.
QRMP (quarterly) filers: 22nd or 24th of the month after the quarter, depending on your state.
QRMP taxpayers still pay tax monthly (via PMT-06) for the first two months of the quarter, even though the return is quarterly.

5Late fees and interest

Filing late costs you on two counts:

Late fee: ₹50 per day (₹25 CGST + ₹25 SGST), or ₹20 per day for a nil return, subject to a cap that varies with turnover.
Interest: 18% per annum on the net tax paid late, under Section 50, calculated from the due date until payment.

💡 ExampleA shop owner files GSTR-3B 10 days late with ₹40,000 net tax due. Late fee ≈ ₹500 (₹50 × 10 days), plus interest of about ₹40,000 × 18% × 10/365 ≈ ₹197. Small here, but it compounds fast on larger liabilities and longer delays.

6The return is now largely locked to your GSTR-1 and 2B

GSTR-3B used to be a self-declared summary you could fill in freely. That is no longer the case in practice.

The outward supply figures are auto-populated from your GSTR-1, and the input tax credit fields are auto-populated from GSTR-2B. Editing those figures downward is restricted, and any variance is visible to the department immediately rather than at audit.

The practical consequence is that GSTR-3B is no longer where you fix a mistake. If the outward figure is wrong, the correction belongs in GSTR-1 or GSTR-1A; if the credit figure is wrong, the correction lies with your supplier's filing.

✅ TipReconcile before you file, not after. Once 3B is filed for a period it cannot be revised, and the correction has to be carried into a later period.

7The QRMP scheme, and what it does not defer

Taxpayers with turnover up to ₹5 crore may opt for the Quarterly Return Monthly Payment scheme, filing GSTR-3B once a quarter instead of monthly — by the 22nd or 24th of the month following the quarter, depending on the state of registration.

What QRMP does not do is defer the tax. Payment remains monthly, through Form PMT-06 by the 25th of each of the first two months of the quarter, either on a fixed-sum basis or on self-assessment.

Missing those monthly payments attracts interest even though the return itself is not yet due, which is the most common misunderstanding about the scheme.

8Why the sequence matters more than the deadline

GST returns file in strict order. A period cannot be filed while an earlier one is outstanding, so a single missed month blocks every month after it.

Late fees then accrue on all of the blocked periods at once, and the taxpayer discovers a compounding liability rather than a single missed deadline. A nil return is still a return for this purpose — filing nothing because there was no business does not keep the sequence intact.

⚠️ ImportantThis is why a dormant registration is expensive to leave open. If the business has genuinely stopped, cancelling the registration costs far less than accumulating nil-return late fees.

9Interest runs on the cash portion, not the whole liability

Where GSTR-3B is filed late, interest at 18% per annum is charged — but the base has been settled in a way that matters.

Interest is payable on the net tax liability discharged in cash, not on the gross output tax, provided the return is filed before any proceedings under sections 73 or 74 have begun. Credit lying in the electronic credit ledger is not treated as tax you delayed paying.

The late fee is separate and runs per day per return, subject to the prescribed caps, and it applies to a nil return as well.

⚠️ ImportantThis distinction was introduced to correct a genuinely punitive earlier position, and calculators built before it still overstate interest substantially.

Key takeaways

GSTR-3B is the summary return where you declare sales, claim ITC and pay net GST.
Reconcile with GSTR-2B first — you can only claim ITC that appears there.
File on the portal: Table 3.1 (sales), Table 4 (ITC), pay via challan, file with EVC/DSC.
Due 20th monthly, or 22nd/24th for QRMP quarterly filers.
Late filing: ₹50/day (₹20 nil) + 18% interest on unpaid tax — and it blocks your next returns.

Frequently asked questions

What is the difference between GSTR-1 and GSTR-3B?

GSTR-1 is the detailed, invoice-level statement of your outward supplies. GSTR-3B is the summary return where you declare totals, claim ITC and pay tax. Both must be filed; GSTR-1 feeds your buyers' GSTR-2B.

Can I revise GSTR-3B after filing?

No — GSTR-3B can't be revised once filed. You correct errors in a later period's return (adjusting the figures) or through the annual return. This is why reconciliation before filing matters so much.

Do I have to file GSTR-3B if there were no sales?

Yes — you must file a nil GSTR-3B for any period with no business. Skipping it blocks your subsequent returns and can attract a late fee for the nil return.

What is the QRMP scheme?

QRMP (Quarterly Return Monthly Payment) lets small taxpayers (turnover up to ₹5 crore) file GSTR-1 and GSTR-3B quarterly while paying tax monthly via a simple challan. It cuts the filing workload for small businesses.

Can I edit the auto-populated figures in GSTR-3B?

Only within limits. Outward supplies are auto-populated from GSTR-1 and credit from GSTR-2B, and reducing those figures is restricted and immediately visible. A wrong outward figure belongs in GSTR-1 or GSTR-1A; a wrong credit figure lies with your supplier's filing.

Under QRMP, do I only pay tax once a quarter?

No — only the return is quarterly. Tax is still paid monthly through Form PMT-06 by the 25th of each of the first two months of the quarter. Missing those attracts interest even though the return is not yet due, which is the most common misunderstanding about the scheme.

What are the QRMP return due dates?

GSTR-3B is due by the 22nd or the 24th of the month following the quarter, depending on the state of registration. Monthly filers file by the 20th of the following month.

I missed one month — can I file the current one first?

No. GST returns file in strict sequence, so one missed period blocks every later period and late fees accrue on all of them at once. A nil return still counts as a return for this purpose.

Is interest charged on my whole GST liability if I file late?

No. Interest at 18% per annum applies to the net liability discharged in cash, not the gross output tax, provided the return is filed before proceedings under section 73 or 74 begin. Credit sitting in the electronic credit ledger is not treated as tax you delayed. The late fee is separate and applies even to a nil return.