GSTR-3B Filing Guide: Sections, Due Dates and Late Fee (2026)

GSTR-3B is the self-declared summary return in which you report your net GST liability for the period and actually pay it. While GSTR-1 is a detailed invoice statement, GSTR-3B is where tax and credit meet the ledgers. This guide walks through the form section by section, shows how data flows in from GSTR-1 and GSTR-2B, and sets out the interest and late fee that apply when deadlines slip.

GSTR-3B Due Dates for 2026

The portal publishes the state-wise group list, so confirm your group rather than assume it. The quarterly dates follow the quarter in which the supplies were made, and QRMP filers additionally pay monthly tax by the 25th under their chosen payment method.

The Filing Sequence: GSTR-1 First, Then 3B

GSTR-1 is due by the 11th and GSTR-3B by the 20th, and that order is deliberate. Once GSTR-1 is filed, your outward supplies auto-populate into GSTR-3B, removing manual entry and transcription errors. The credit side arrives through GSTR-2B, which is drafted from your suppliers’ filings — so filing your own GSTR-1 early also helps everyone downstream in the chain.

File GSTR-3B only after reconciling your purchase records against GSTR-2B, because the 3B locks the tax payment for the period. Corrections to GSTR-1 records happen through GSTR-1A before the 3B is filed, keeping the two returns aligned.

Section-Wise Guide to the Form

Reverse charge deserves special care: the tax must be paid in cash only, not from credit, and the corresponding ITC is then claimed separately where eligible. Treat auto-population as a convenience, not a guarantee — verify the pulled-outward figures before submitting, since errors here flow straight into the payment.

The DRC-01C Risk: When GSTR-1 and 3B Do Not Match

If the ITC you claim in GSTR-3B exceeds what GSTR-2B supports, or your declared liability diverges from GSTR-1, the department can issue a system-generated intimation in Form DRC-01C. You respond through Form DRC-01A — either accepting the difference and paying tax with interest, or explaining it with documents and reconciliation. Ignoring the intimation can lead to an adverse order and recovery, so treat any mismatch alert as urgent. A disciplined GSTR-1-first sequence plus a 2B reconciliation before filing closes most of this risk at the source.

Interest and Late Fee on GSTR-3B

Missing the deadline costs money on two fronts. Interest hits the tax paid late, and late fee hits the return itself:

• Interest at 18% per annum on tax paid late, calculated on the cash payment from the due date to the date of deposit.
• Late fee of ₹50 per day (₹25 CGST + ₹25 SGST) for delayed filing, reduced to ₹20 per day (₹10 + ₹10) for nil returns.

Late fee is capped by aggregate annual turnover (AATO): ₹5,000 where AATO is up to ₹1.5 crore, ₹10,000 between ₹1.5 crore and ₹5 crore, and ₹20,000 above ₹5 crore — each cap being split between CGST and SGST. Estimate your exact exposure with our GST late fee calculator before you file. Repeated defaults can flag a registration for scrutiny or suspension, so where arrears have piled up, a GST consultant can sequence the filings and settlement properly.

Key Takeaways

• GSTR-3B is due by the 20th monthly; QRMP filers file by the 22nd (Group 1) or 24th (Group 2) after the quarter.
• Outward supplies auto-pull from GSTR-1; ITC comes from GSTR-2B; reverse charge is paid in cash only.
• File GSTR-1 by the 11th so the data flows in cleanly before the 20th.
• Excess ITC or liability mismatches invite a DRC-01C intimation; respond through DRC-01A promptly.
• Late payment draws 18% interest; late fee is ₹50 per day (₹20 for nil), capped at ₹5,000, ₹10,000 or ₹20,000 by turnover.

Frequently Asked Questions

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

GSTR-1 reports invoice-level details of outward supplies, while GSTR-3B is the summary return in which liability is declared and tax is paid. Your buyers’ credit depends on GSTR-1; the government’s cash flow depends on GSTR-3B.

When is GSTR-3B due under the QRMP scheme?

By the 22nd of the month after the quarter for Group 1 states, and the 24th for Group 2 states. Monthly tax under QRMP is still paid by the 25th of each month under the fixed-sum or self-invoice method.

Can I claim ITC that is not in my GSTR-2B?

No. Input tax credit can be claimed only for documents that appear in your GSTR-2B, as required by Section 16(2)(aa). Chase the supplier to file GSTR-1 rather than claiming unreconciled credit, which invites a DRC-01C intimation.

How is interest calculated on late payment of GST?

Interest runs at 18% per annum on the tax paid in cash after the due date, for the exact days of delay. It is computed automatically when you create the challan for the arrears.

What is the late fee for filing GSTR-3B late?

₹50 per day — ₹25 CGST plus ₹25 SGST — and ₹20 per day for nil returns, subject to turnover-based caps of ₹5,000, ₹10,000 or ₹20,000. Use a late fee calculator to estimate the amount before filing.

Do I pay reverse charge tax through the credit ledger?

No. Reverse charge liability must be discharged in cash through the electronic cash ledger. The ITC on such inward supplies is claimed separately where eligible.

Disclaimer: Tax laws change frequently. Verify current rates and deadlines on the official portals (incometax.gov.in, gst.gov.in) or consult a qualified professional before acting.