GSTR-1 vs GSTR-3B: What’s the Difference and Which One Do You Pay Tax In? (2026)

What is GSTR-1?

GSTR-1 is your sales report. Every month (or every quarter, if you are on the QRMP scheme), you list what you sold.

The details are invoice-level. For sales to other businesses (B2B), you enter each invoice separately: the buyer’s GSTIN, invoice number, date, value, and tax rate. For sales to ordinary customers (B2C), you give a summary by tax rate. You also report exports, credit notes, and debit notes here.

Why does this matter? Because your GSTR-1 feeds directly into your buyers’ GSTR-2B. If you don’t report an invoice in your GSTR-1, your buyer cannot see it in their GSTR-2B, and they cannot claim input tax credit (ITC) on it. Late GSTR-1 filing doesn’t just hurt you — it blocks your customers’ tax credit.

One thing many first-time filers find odd: you pay no tax in GSTR-1. It is a pure reporting return. There is no payment button, no tax column to settle. It only declares what you sold.

Due dates for GSTR-1:

• Monthly filers (turnover above ₹5 crore): 11th of the following month
• QRMP quarterly filers (turnover up to ₹5 crore): 13th of the month following the quarter end
• IFF (Invoice Furnishing Facility, optional for QRMP): 13th of the first two months of the quarter — this lets you report B2B invoices monthly so your buyers don’t have to wait a full quarter for their ITC

What is GSTR-3B?

GSTR-3B is the summary return where you actually settle your tax. No invoice-level detail goes in here — only consolidated totals.

The return has three main jobs:

1. Declare your outward tax liability — the total GST on everything you sold (reported in the liability tables).
2. Claim your input tax credit — the GST you paid on business purchases, shown in Table 4 of the return. Your eligible ITC comes from GSTR-2B, which is generated from your suppliers’ GSTR-1 filings.
3. Pay the net tax — output tax minus ITC, split into CGST, SGST, and IGST. The payment happens as part of filing GSTR-3B.

There is one hard rule about GSTR-3B: it cannot be revised once filed. If you discover a mistake, you fix it in the next period’s GSTR-3B. This is why reconciliation before filing is so important.

Since July 2025, the GST portal auto-populates the outward tax liability tables of GSTR-3B from your GSTR-1 (and GSTR-1A/IFF), and those fields are not editable. You cannot quietly change the figures — the sales you reported and the tax you pay are now locked together by the portal itself.

Due dates for GSTR-3B:

• Monthly filers (turnover above ₹5 crore): 20th of the following month
• QRMP quarterly filers: 22nd of the month following the quarter (Category X states) or 24th (Category Y states)
• QRMP monthly tax payment: Form GST PMT-06 by the 25th of the first two months of each quarter

GSTR-1 vs GSTR-3B: side-by-side comparison

Which one comes first? (The sequence rule)

Always file GSTR-1 before GSTR-3B.

This is not just good practice — the portal enforces it. Under Rule 59(6), your GSTR-1 for a period is blocked if the GSTR-3B of the previous period has not been filed. The whole chain runs in sequence: your suppliers’ GSTR-1 → your GSTR-2B → your GSTR-3B.

The practical rhythm for monthly filers is simple: GSTR-1 by the 11th, then GSTR-3B by the 20th. For QRMP filers: GSTR-1 (or IFF) by the 13th, then GSTR-3B by the 22nd/24th.

What happens when GSTR-1 and GSTR-3B don’t match?

A mismatch between the two returns is one of the fastest ways to get a GST notice. Here’s how it plays out:

• The GST system automatically compares the sales reported in GSTR-1 with the liability declared in GSTR-3B under Rule 88C. If GSTR-1 shows higher sales than what you paid tax on in GSTR-3B, the portal flags it.
• You receive an intimation in Form DRC-01B, asking you to pay the difference or explain it.
• If you ignore the intimation, the department issues a demand notice in Form DRC-01 for the differential tax with interest on top.
• Consistent mismatches can also lead to scrutiny notices (ASMT-10) and, in serious cases, a GST audit.

The fix is dull but effective: reconcile every month. Before filing, check that your books, GSTR-1, GSTR-2B, and GSTR-3B all agree. It takes ten extra minutes and prevents months of notices.

How to fix a mistake

It depends on which return the mistake is in.

Mistake in GSTR-1: Amend it in Table 9 of a later period’s GSTR-1. Or use GSTR-1A — this lets you correct the current period’s GSTR-1 before you file GSTR-3B. Because the July 2025 auto-population locks GSTR-3B’s liability tables to your GSTR-1 data, fixing GSTR-1 (or GSTR-1A) first keeps everything consistent.

Mistake in GSTR-3B: You cannot revise it. The correction goes into the next period’s GSTR-3B. Under-reported tax? Pay the difference (with interest) in the next 3B. Over-claimed ITC? Reverse it in the next 3B.

The one thing you must never do: file GSTR-3B with figures that differ from GSTR-1 and hope nobody notices. The portal’s auto-population and Rule 88C matching make that gap visible by default now.

Late fees and interest

Skipping either return costs money:

• Late fee (both returns): ₹50 per day under CGST plus ₹50 per day under SGST, subject to a maximum cap that depends on your turnover: nil returns are capped at ₹500, and normal returns at ₹2,000, ₹5,000, or ₹10,000 depending on your annual turnover slab.
• Interest on late tax payment: 18% per annum on the net cash tax liability (the amount you actually owe after ITC), counted from the day after the due date.
• Nil returns: Both nil GSTR-1 and nil GSTR-3B are mandatory. Having no sales does not mean you can skip filing — the late fee applies even to nil returns.
• Filing blocks: Two consecutive periods of non-filing can get your GSTIN suspended, and it blocks your buyers’ ITC chain as well.

What freelancers should know

If you are a freelancer with GST registration, you will almost certainly file under the QRMP scheme (turnover up to ₹5 crore). That means:

• GSTR-1 quarterly by the 13th of the month after the quarter ends. If you have B2B clients who want their ITC quickly, use the optional IFF to report those invoices on the 13th of each of the first two months of the quarter.
• GSTR-3B quarterly by the 22nd/24th, with monthly tax payment through PMT-06 by the 25th in the first two months of the quarter.
• Foreign clients: If you export services under LUT, report those invoices as exports in GSTR-1. (We covered the full freelancer workflow — threshold, 18% rate, LUT — in our GST for freelancers guide.)
• ITC on business expenses: Software subscriptions, equipment, co-working space — the GST you pay on these appears in your GSTR-2B when your suppliers file, and you claim it in GSTR-3B Table 4. Claim only what GSTR-2B shows; the days of claiming provisional ITC are over.

Reconciliation checklist (before you hit submit)

1. Your sales register total = GSTR-1 total for the period.
2. Your GSTR-2B ITC = what you claim in GSTR-3B Table 4 (claim only eligible ITC; reverse anything blocked under Section 17(5)).
3. Your GSTR-1 liability = GSTR-3B outward liability (the portal auto-populates this now, but check it).
4. Debit/credit notes are in the right tables and the right period.
5. Nil periods have nil returns filed for both forms.

Frequently asked questions

Can I file GSTR-3B without filing GSTR-1 first?

You should not. The sequence is enforced by the portal — Rule 59(6) blocks GSTR-1 when an earlier period’s GSTR-3B is pending, and since July 2025 the GSTR-3B liability tables auto-populate from GSTR-1, so filing 3B before finalising GSTR-1 risks an automatic mismatch. Always file GSTR-1 first.

What happens if my GSTR-1 and GSTR-3B don’t match?

The system flags the difference automatically under Rule 88C and sends you a DRC-01B intimation to pay the difference or explain it. If you ignore it, a demand notice (DRC-01) follows for the differential tax with interest. Repeated mismatches can trigger scrutiny notices and audits.

Can GSTR-3B be revised after filing?

No. There is no revision facility for GSTR-3B. Corrections — underpaid tax, over-claimed ITC — go into the next tax period’s GSTR-3B, with interest where tax was short-paid. This is why reconciling before filing matters so much.

Do I need to file both returns if I had zero sales?

Yes. Nil GSTR-1 and nil GSTR-3B are both mandatory for every registered taxpayer, including under QRMP. Zero business activity does not cancel the filing obligation, and late fees apply to nil returns too.

Which return should I file first, GSTR-1 or GSTR-3B?

GSTR-1 first. File it by the 11th (monthly) or 13th (QRMP), then file GSTR-3B by the 20th (monthly) or 22nd/24th (QRMP). Filing in this order keeps your data, your buyers’ ITC, and the portal’s auto-population consistent.

What are the late fees for GSTR-1 and GSTR-3B?

₹50 per day under CGST plus ₹50 per day under SGST, capped by notification: nil returns capped at ₹500, and normal returns at ₹2,000, ₹5,000, or ₹10,000 depending on your annual turnover. On top of that, late tax payment attracts 18% per annum interest on the net cash liability.

Does GSTR-1 include my purchase invoices?

No. GSTR-1 is only for outward supplies — what you sold. Your purchases appear automatically in your GSTR-2B based on your suppliers’ GSTR-1 filings. You then claim the ITC in Table 4 of GSTR-3B.

Official sources

• GST Portal (gst.gov.in) — file returns, check GSTR-2B, and download return formats
• CBIC (cbic.gov.in) — GST notifications and circulars, including late-fee and Rule 88C provisions
• GST Tutorial / Help (tutorial.gst.gov.in) — official step-by-step filing guides

Priya Sharma

Editorial byline for eircicai GST guides — covering registration, return filing, rates, and compliance for small businesses. Content is reviewed by Asuthod Rathod, CA.