GSTR-1 vs GSTR-3B

A Complete, Practical Guide to India's Two Most Important GST Returns (Updated for 2026)

By Tax Esquire — Tax, GST, Legal & Business Compliance Specialists

Introduction

If you run a GST-registered business in India, two return forms will follow you every single month (or quarter): GSTR-1 and GSTR-3B. They sound similar, they are due around the same time, and both live on the GST portal — yet they serve completely different purposes. Confusing the two, or filing one without properly matching it to the other, is one of the most common reasons Indian businesses receive GST notices.

This guide breaks down GSTR-1 vs GSTR-3B in plain English — what each form is for, who must file them, the exact steps to file, the documents you need, the late fees involved, and the mistakes that trip up even experienced accountants. We have also included comparison tables, checklists, and real examples so you can use this as a ready reference every filing season.

Note: GST rules are updated frequently by the CBIC and GST Council. This guide reflects the rules applicable for FY 2026-27, including the hard-locking of auto-populated liability figures and the GSTR-1A correction window. Always cross-check the latest notifications on the official GST portal (www.gst.gov.in) before filing.

Quick Summary: GSTR-1 vs GSTR-3B in One Line

In the simplest terms: GSTR-1 tells the government (and your buyers) what you sold, invoice by invoice. GSTR-3B tells the government how much tax you owe and actually pays it, in summary form. One is a sales report; the other is a tax payment return. Both are compulsory, both are linked, and mismatches between them are the single biggest trigger for GST scrutiny notices.

 

What is GSTR-1?

GSTR-1 is a monthly or quarterly return under Section 37 of the CGST Act, 2017, in which every regular GST-registered supplier reports the details of outward supplies — that is, sales of goods and services. It is filed invoice-wise, which means individual invoice numbers, dates, buyer GSTINs, taxable values, and tax amounts must be reported.

The data you upload in GSTR-1 does not stay with you — it flows directly into your buyers' GSTR-2B (their auto-generated input tax credit statement). This is why timely and accurate GSTR-1 filing is not just a compliance formality; it is a direct commercial obligation to every customer who wants to claim ITC on your invoice.

What is GSTR-3B?

GSTR-3B is a self-declared summary return where a business reports consolidated figures — total outward supplies, eligible input tax credit, reverse charge liability, and net GST payable — and then pays the tax due. Unlike GSTR-1, GSTR-3B does not require invoice-level detail; it only needs summary totals across a handful of tables.

Since the GST portal now auto-populates GSTR-3B from your own GSTR-1 filings (Table 3.1 and 3.2) and from GSTR-2B (ITC in Table 4), GSTR-3B has effectively become a review-and-pay return rather than a from-scratch data entry exercise. From late 2025 onwards, several of these auto-populated fields have been hard-locked, meaning you can no longer freely edit them inside GSTR-3B — corrections must be routed through GSTR-1A instead.

 

Benefits of Filing GSTR-1 and GSTR-3B Correctly and On Time

Filing both returns accurately isn't just about avoiding penalties — it directly protects your cash flow, your reputation with customers, and your standing with the tax department.

•     Uninterrupted Input Tax Credit for your buyers: your customers can only claim ITC on invoices that appear in their GSTR-2B, which is built from your GSTR-1.

•     Fewer notices and audits: accurate GSTR-1 vs GSTR-3B reconciliation is the first thing GST officers check; clean data means fewer scrutiny notices under Section 61.

•     Better GST compliance rating: consistent, on-time filing improves your compliance score, which matters for e-way bill generation, refunds, and vendor onboarding.

•     Avoids interest at 18-24% per annum: timely payment through GSTR-3B prevents interest charges under Section 50 of the CGST Act.

•     Smooth loan and tender eligibility: banks and government tenders often ask for GST return filing history as proof of business genuineness.

•     Accurate financial reporting: reconciled GST data makes your books, balance sheet, and GSTR-9 annual return preparation far easier at year-end.

 

Eligibility: Who Must File GSTR-1 and GSTR-3B?

Eligibility Table

Criteria	GSTR-1	GSTR-3B
Applicable to	All regular registered taxpayers (including nil filers)	All regular registered taxpayers (including nil filers)
Turnover > Rs. 5 crore	Monthly filing mandatory	Monthly filing mandatory
Turnover up to Rs. 5 crore	Monthly or Quarterly (QRMP)	Monthly or Quarterly (QRMP)
Composition dealers	Not applicable (file GSTR-4 instead)	Not applicable
Input Service Distributors (ISD)	Not applicable	Not applicable
Non-resident taxable persons	Not applicable (file GSTR-5)	Not applicable
Nil transactions in the period	Nil GSTR-1 still required	Nil GSTR-3B still required

 

Even a dormant GSTIN with zero sales and zero purchases must file Nil GSTR-1 and Nil GSTR-3B every period until the registration is formally cancelled or suspended.

 

GSTR-1 vs GSTR-3B: Detailed Comparison Chart

Parameter	GSTR-1	GSTR-3B
Purpose	Reports outward supplies (sales) invoice-wise	Summary of sales, ITC and net tax payable
Legal basis	Section 37, CGST Act 2017	Section 39, CGST Act 2017
Level of detail	Invoice-level (B2B, B2C, exports, credit/debit notes)	Consolidated totals only
Tax payment	No tax is paid with this return	Tax liability is discharged here
Due date (monthly)	11th of the following month	20th of the following month
Due date (QRMP quarterly)	13th of the month after the quarter	22nd or 24th of the month after the quarter (state-wise)
Editable after filing?	Amend via GSTR-1A of the same period, or in the next period's GSTR-1	Cannot be revised; correct in the next month's return
Impact on buyer	Populates buyer's GSTR-2B for ITC claim	No direct effect on buyer's ITC
Sequential filing rule	Must be filed before GSTR-3B for the period	Blocked until GSTR-1 (or IFF) for the period is filed
Auto-population	Manually entered by the supplier	Auto-populated from GSTR-1 (sales) and GSTR-2B (ITC)

 

Step-by-Step Process to File GSTR-1

1.   Log in to the GST portal at www.gst.gov.in using your GSTIN credentials.

2.   Go to Services > Returns > Returns Dashboard.

3.   Select the relevant Financial Year and Return Filing Period (month or quarter).

4.   Click 'Prepare Online' or 'Prepare Offline' (using the GSTR-1 offline utility for bulk invoice uploads) under the GSTR-1 tile.

5.   Fill in each applicable table: B2B invoices, B2C (large and small), exports, credit/debit notes, HSN-wise summary, and documents issued.

6.   QRMP taxpayers can optionally use the Invoice Furnishing Facility (IFF) in Month 1 and Month 2 of the quarter, due by the 13th of the following month, so buyers get ITC monthly instead of waiting for the quarterly GSTR-1.

7.   Preview the summary, verify invoice totals against your sales register, and check for GSTIN validation errors.

8.   Submit the return to freeze the data, then proceed to file with either an OTP-based EVC or a Digital Signature Certificate (DSC), mandatory for companies and LLPs.

9.   Download the filed GSTR-1 acknowledgement (ARN) for your records.

Step-by-Step Process to File GSTR-3B

10.       Log in to the GST portal and navigate to Services > Returns > Returns Dashboard.

11.       Select the financial year and period; click 'Prepare Online' under the GSTR-3B tile.

12.       Review the auto-populated figures in Table 3.1 (outward supplies) and Table 3.2 (inter-state supplies to unregistered persons/composition/UIN holders) — these are now largely non-editable and pulled directly from your filed GSTR-1/1A/IFF.

13.       If Table 3.1 or 3.2 figures are wrong, do not try to overwrite them; instead file a correction through GSTR-1A for the same period before proceeding.

14.       Check Table 4 (Eligible ITC) against your downloaded GSTR-2B statement and reverse any ineligible or blocked credits under Section 17(5).

15.       Complete Table 5 (values of exempt, nil-rated, and non-GST inward supplies) and Table 6.1 (payment of tax).

16.       Use the 'RE-COMPUTE INTEREST' button in Table 5.1 if the auto-calculated interest looks incorrect after you update figures.

17.       Open and save the 'Tax Liability Breakup' tab on the payment page — this step is now mandatory even for nil cash payments.

18.       Generate the challan (if cash payment is needed), pay through net banking, NEFT/RTGS, or over-the-counter, and offset the liability using ITC and cash.

19.       File the return using EVC or DSC and download the acknowledgement.

 

Documents Required for Filing GSTR-1 and GSTR-3B

For GSTR-1

•     Sales invoices (B2B and B2C) issued during the period

•     Credit notes and debit notes issued to customers

•     Export invoices and shipping bill details, if applicable

•     HSN/SAC-wise summary of goods and services supplied

•     Details of advances received (where applicable)

•     Buyer GSTIN details for all B2B transactions

For GSTR-3B

•     Sales register (matched with filed GSTR-1)

•     Purchase register for claiming input tax credit

•     GSTR-2B statement downloaded from the GST portal

•     Import bill of entry copies, for goods imported during the period

•     Details of reverse charge liability, if any

•     Previous month's electronic credit and cash ledger balances

 

Late Fees and Penalties

Both returns attract late fees for delayed filing, and GSTR-3B additionally attracts interest on any tax paid late.

Return	Late Fee (with tax liability)	Late Fee (Nil return)	Maximum Cap
GSTR-1	Rs. 50 per day (Rs. 25 CGST + Rs. 25 SGST)	Rs. 20 per day (Rs. 10 CGST + Rs. 10 SGST)	Rs. 5,000 (or as capped by notification based on turnover)
GSTR-3B	Rs. 50 per day (Rs. 25 CGST + Rs. 25 SGST)	Rs. 20 per day (Rs. 10 CGST + Rs. 10 SGST)	Rs. 5,000 (or as capped by notification based on turnover)

 

In addition to the late fee, GSTR-3B attracts interest under Section 50 of the CGST Act at 18% per annum on the net tax liability, calculated from the day after the due date until the actual date of payment. Where ITC is wrongly availed and utilised, the interest rate increases to 24% per annum on the amount wrongly used.

Example: If your net GST liability for a month is Rs. 1,00,000 and you file 30 days late, interest payable works out to approximately Rs. 1,479 (Rs. 1,00,000 x 18% x 30/365), in addition to the applicable late fee. The CBIC occasionally announces amnesty schemes waiving part of the late fee for old pending returns — always check for an active amnesty notification before clearing a backlog.

 

Common Mistakes to Avoid

Most GST notices trace back to a handful of recurring, avoidable errors. Use this checklist before you hit 'File' each month.

☐  Filing GSTR-3B before GSTR-1 for the same period — sequential filing is mandatory; GSTR-3B is blocked until GSTR-1 or IFF is filed.

☐  Under-reporting outward supplies in GSTR-3B compared to invoices already uploaded in GSTR-1.

☐  Claiming ITC in GSTR-3B that does not appear in GSTR-2B — this is now restricted under Rule 36(4).

☐  Ignoring blocked credits under Section 17(5), such as motor vehicles for personal use or club memberships.

☐  Trying to manually overwrite the now-locked figures in Table 3.1/3.2 of GSTR-3B instead of correcting through GSTR-1A.

☐  Missing reverse charge liability on specified inward supplies in Table 3.1.1.

☐  Entering the wrong buyer GSTIN in GSTR-1, which prevents the invoice from ever reaching the buyer's GSTR-2B.

☐  Forgetting that GSTR-3B, once filed, cannot be revised — errors must be corrected in the following month.

☐  Skipping Nil returns entirely, assuming 'no transactions' means 'no filing required'.

☐  Not reconciling GSTR-1, GSTR-3B and GSTR-2B every month, leading to a pile-up of mismatches by year-end that becomes very difficult to untangle for GSTR-9 and GSTR-9C.

 

Frequently Asked Questions (FAQs)

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

GSTR-1 reports invoice-level details of your sales, while GSTR-3B is a summary return used to declare and pay your net GST liability. GSTR-1 feeds your buyers' ITC; GSTR-3B is where tax actually gets paid.

2. Can I file GSTR-3B without filing GSTR-1?

No. Since January 2022, sequential filing has been enforced — GSTR-3B cannot be filed for a period until the corresponding GSTR-1 or IFF has been filed for that same period.

3. What happens if GSTR-1 and GSTR-3B figures do not match?

A mismatch between GSTR-1 and GSTR-3B is one of the most common triggers for a GST scrutiny notice under Section 61. The department typically asks the taxpayer to explain the difference and may demand tax with interest and penalty if it represents suppressed sales.

4. Is GSTR-3B revisable if I make a mistake?

No, GSTR-3B cannot be revised once filed. Any correction must be carried forward and adjusted in the GSTR-3B of a subsequent tax period.

5. Can GSTR-1 be corrected after filing?

Yes. Errors in a filed GSTR-1 can be corrected through GSTR-1A for the same period, or through amendment tables in a later month's or quarter's GSTR-1.

6. What is the due date for GSTR-1 and GSTR-3B for monthly filers?

GSTR-1 is due on the 11th of the following month, and GSTR-3B is due on the 20th of the following month, for taxpayers with aggregate turnover above Rs. 5 crore or those who have not opted for QRMP.

7. What is the QRMP scheme and how does it change these due dates?

QRMP (Quarterly Return Monthly Payment) is available to taxpayers with turnover up to Rs. 5 crore. Under QRMP, GSTR-1 is filed quarterly (due on the 13th of the month after the quarter), and GSTR-3B is also filed quarterly (due on the 22nd or 24th, depending on the state), while tax is still paid monthly through the PMT-06 challan for the first two months of the quarter.

8. Do I need to file GSTR-1 and GSTR-3B if I had no sales in a month?

Yes. A Nil GSTR-1 and Nil GSTR-3B must still be filed for every period, even with zero transactions, until your GST registration is cancelled.

9. What is GSTR-1A and why does it matter now?

GSTR-1A allows a supplier to add or correct invoice details for the same tax period before filing GSTR-3B. Since GSTR-3B now auto-populates certain sales tables from GSTR-1 in a locked, non-editable format, GSTR-1A has become the primary route to fix errors before the summary return is filed.

10. What is the penalty for filing GSTR-1 or GSTR-3B late?

Both returns attract a late fee of Rs. 50 per day (Rs. 20 per day for Nil returns), subject to a maximum cap, split equally between CGST and SGST. GSTR-3B additionally attracts interest at 18% per annum on unpaid tax (24% for wrongly availed and utilised ITC), calculated from the due date until the date of actual payment.

 

Conclusion

GSTR-1 and GSTR-3B are two halves of the same compliance obligation — one tells the story of what you sold, and the other settles what you owe. Filing them accurately, on time, and in sync with each other protects your input tax credit chain, keeps your compliance rating healthy, and keeps GST notices away from your inbox.

With auto-population, hard-locking of key tables, and the GSTR-1A correction window now built into the GST portal, the process rewards businesses that get their sales data right the first time in GSTR-1, rather than trying to fix things later inside GSTR-3B.

Staying on top of monthly due dates, reconciling GSTR-2B before every ITC claim, and maintaining clean invoice records is not just good practice — it is the difference between a smooth annual return season and a stressful one.

How Tax Esquire Can Help

Keeping GSTR-1 and GSTR-3B accurate every month — while tracking due dates, reconciling GSTR-2B, and staying current with fast-changing GST notifications — takes real bandwidth. Tax Esquire works with businesses and professionals across India as a trusted partner for GST return filing, reconciliation, notice handling, and broader tax, legal, and business compliance needs, so you can focus on running your business while the filings are handled accurately and on time.

Whether you are setting up GST compliance for a new business, clearing a backlog of pending returns, or simply want a second pair of expert eyes on your monthly filings, Tax Esquire's team of chartered accountants and GST practitioners is available to help you file correctly, avoid penalties, and stay fully compliant.

Need help with your GST filings? Reach out to Tax Esquire today for accurate, timely GSTR-1 and GSTR-3B filing support, GST reconciliation, and end-to-end compliance management.

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