How to File GSTR-1 & GSTR-3B Correctly – Step-by-Step Guide 2025

Navigating the complexities of GST compliance can be a major challenge for Indian businesses. The constant pressure to meet deadlines and the fear of making errors that could lead to notices, penalties, and interest can be overwhelming. To stay compliant and avoid financial strain, it is essential to master the process and file GSTR-1 & GSTR-3B correctly. These two returns form the backbone of your GST obligations, and understanding how they work together is the first step towards a stress-free compliance journey. This comprehensive guide is designed to demystify the process, breaking down each step into simple, actionable instructions to help you file your GST returns with confidence in 2025. For a broader overview, you can also refer to our guide on How to File GST Returns Online: A Step-by-Step Guide of the GST Filing Process & Procedure.

Understanding GSTR-1 and GSTR-3B: The Basics

Before diving into the filing process, it’s crucial to understand the purpose of each return and how they interact. Think of GSTR-1 as a detailed report of your sales and GSTR-3B as a summary where you settle your tax dues.

What is GSTR-1? The Statement of Your Outward Supplies

GSTR-1 is the return where every registered taxpayer declares the details of their outward supplies—in simple terms, all their sales transactions for a specific tax period. It is essentially a detailed statement of every invoice you have issued to your customers. This return is mandatory for all regular taxpayers registered under GST, including those who have opted for the QRMP (Quarterly Return Monthly Payment) scheme.

The information you need to provide in GSTR-1 is comprehensive and includes:

B2B Invoices: Details of sales made to other GST-registered businesses.
B2C Invoices: Details of sales to unregistered consumers. Large inter-state invoices (over ₹2.5 lakhs) are reported individually, while others are consolidated.
Credit and Debit Notes: Any adjustments made to previously issued invoices.
HSN-wise Summary: A summary of all goods and services supplied, categorized by their Harmonized System of Nomenclature (HSN) codes.

Due Dates for GSTR-1:

Monthly Filers: 11th of the next month.
Quarterly Filers (QRMP Scheme): 13th of the month following the end of the quarter.

What is GSTR-3B? The Summary Return and Tax Payment

GSTR-3B is a self-declared summary return that consolidates your sales, purchases, and tax liability for the month. This is the return through which you actually pay your GST dues to the government. Every regular taxpayer must file GSTR-3B. It provides a summary of your outward supplies, the Input Tax Credit (ITC) you are claiming, and your net tax liability after setting off the ITC. This return aggregates data on sales, purchases that are subject to reverse charge, and the total eligible ITC you can claim for the period.

Due Dates for GSTR-3B:

Monthly Filers: 20th of the next month.
Quarterly Filers (QRMP Scheme): 22nd or 24th of the month following the quarter, depending on your state or union territory.

The Crucial Link: How GSTR-1 and GSTR-3B Work Together

GSTR-1 and GSTR-3B are deeply interconnected. The data you enter in your GSTR-1 is not just a record of your sales; it directly impacts both your GSTR-3B and your customer’s ability to claim ITC. When you correctly file GSTR-1, the total sales figures are automatically populated in Table 3 of your GSTR-3B, ensuring consistency. Furthermore, the B2B invoice details from your GSTR-1 appear in your recipients’ GSTR-2A and GSTR-2B statements. This is the foundation upon which they claim their Input Tax Credit.

This seamless flow of information highlights the importance of how to file GSTR-1 correctly India. Any mistake in your GSTR-1 can prevent your customer from getting their rightful credit, potentially damaging your business relationships. It is absolutely essential to ensure that the total tax liability declared in your GSTR-3B precisely matches the total sales reported in your GSTR-1 for the same period. Any mismatch will trigger an automated notice from the GST system, leading to unnecessary complications.

Pre-Filing Checklist: Get Ready for a Smooth Filing Experience

A little preparation goes a long way in ensuring an error-free filing experience. Before you log in to the GST portal, gather all the necessary documents and perform a quick reconciliation to catch any discrepancies early.

Essential Documents and Information Needed

Have the following ready before you begin:

A complete list of all sales invoices issued during the tax period, ensuring the GSTINs of your B2B customers are correct.
All Debit and Credit Notes issued to customers.
The corresponding HSN/SAC codes for all goods and services you have supplied.
A record of all purchase invoices to reconcile with the auto-populated data in your GSTR-2B for accurate ITC claims.
Your login credentials (Username and Password) for the official GST Portal.
A valid Digital Signature Certificate (DSC) for companies and LLPs, or access to the mobile number registered with your Aadhaar for EVC (Electronic Verification Code) for other taxpayers.

Reconciling Your Data: The Most Important Step

This is perhaps the most critical pre-filing activity. Before you even think about entering data on the portal, take the time to reconcile your accounting records with the source documents. Whether you use accounting software like Tally or Zoho Books, or manage your finances in Excel sheets, cross-check your sales register, purchase register, and credit/debit note records. This simple act of verification ensures that the data you are about to file is accurate and complete, which is the foundation for filing GSTR-1 and GSTR-3B effectively.

The Step-by-Step GSTR-1 Filing Process

Once your data is reconciled and your documents are in order, you can proceed with filing GSTR-1 on the portal.

Step 1: Log in and Navigate to the GSTR-1 Dashboard

First, visit the official GST portal at https://www.gst.gov.in/ and log in with your credentials. Once you are on your dashboard, follow this path: Services -> Returns -> Returns Dashboard. Here, you will be prompted to select the Financial Year and the Return Filing Period (month or quarter) for which you want to file the return.

Step 2: Adding Invoice Details in GSTR-1 Tables

On the GSTR-1 page, you will see various tiles or tables, each corresponding to a specific type of supply. You can add details directly online or use the offline utility for a large number of invoices. For online filing, you need to enter data into the relevant tables:

Table 4 (B2B): This is for reporting all your sales to other registered taxpayers. You must provide invoice-wise details, including the recipient’s GSTIN, invoice number, date, value, and tax details.
Table 5 (B2C Large): Use this table for inter-state sales made to unregistered persons (consumers) where the invoice value is more than ₹2.5 lakhs.
Table 7 (B2C Others): This table is for reporting a consolidated, rate-wise summary of all other B2C sales (i.e., intra-state sales of any value and inter-state sales below ₹2.5 lakhs).
Table 9B (Credit/Debit Notes – Registered): Report any credit or debit notes issued against B2B invoices here.
Table 12 (HSN Summary): Provide a summary of all goods and services supplied, categorized by their HSN/SAC codes and quantities.

Step 3: Generate Summary, Preview, and Submit

After entering all the details in the respective tables, scroll to the bottom of the page and click the ‘GENERATE GSTR-1 SUMMARY’ button. The system may take a few minutes to process the data. Once the summary is generated, you can preview it in PDF or Excel format.

Crucial Warning: Review this summary with extreme care. Check every figure against your own records. Once you click the ‘SUBMIT’ button, you cannot make any changes to your GSTR-1 for that tax period. Any errors discovered after submission can only be corrected through an amendment in the GSTR-1 of a subsequent tax period.

Step 4: File GSTR-1 using EVC or DSC

After submitting the return, the ‘FILE RETURN’ button will be enabled. Click on it and proceed to file using either:

EVC (Electronic Verification Code): An OTP will be sent to the mobile number and email ID linked to the authorized signatory’s Aadhaar.
DSC (Digital Signature Certificate): The authorized signatory must use their registered DSC to sign the return.

Upon successful filing, an Acknowledgement Reference Number (ARN) will be generated.

Your Complete GSTR-3B Filing Guide India

With GSTR-1 filed, the next step is to file the summary return, GSTR-3B. The process is now significantly streamlined thanks to auto-population of data.

Step 1: Review Auto-Populated Data from GSTR-1 and GSTR-2B

Navigate back to the Returns Dashboard and select GSTR-3B for the same tax period. The system will now show you auto-drafted data pulled from your other GST filings.

Table 3.1 (Details of Outward Supplies): This table, which shows your sales and tax liability, will be largely auto-populated from the GSTR-1 you just filed. You must verify these figures.
Table 4 (Eligible ITC): The details of your Input Tax Credit will be auto-populated from your GSTR-2B, which is a static statement generated based on the GSTR-1 filed by your suppliers.

Step 2: Confirming Liabilities and Claiming ITC

Your primary task here is to review and confirm the auto-populated numbers. Pay close attention to the ITC details in Table 4. Compare the ITC figures from your GSTR-2B with your own purchase records and accounting books. It is your responsibility to ensure you are only claiming eligible ITC as per GST rules and reversing any credit that is not permissible. For a detailed breakdown, our GST Input Tax Credit (ITC) Full Guide 2025 – Eligibility, Limits & Common Issues can be very helpful. This reconciliation is a vital part of any guide to GSTR-3B filing India.

Step 3: Making the Tax Payment

After you have confirmed all the values in GSTR-3B, click the ‘PROCEED TO PAYMENT’ button. The system will display your total tax liability and how it can be paid. The GST portal will first try to offset your liability against the available balance in your Electronic Credit Ledger (your ITC balance). If there is any remaining tax liability, it must be paid from your Electronic Cash Ledger. If your cash ledger does not have sufficient funds, you will need to create a challan to deposit the required amount via net banking, debit/credit card, or NEFT/RTGS.

Step 4: File GSTR-3B

Once the tax payment is made and the liability is fully offset, the ‘File GSTR-3B’ button becomes active. You can now file the return using either EVC or DSC, similar to the GSTR-1 filing process. This completes your GST filing for the period.

Common Mistakes to Avoid When You File GSTR-1 & GSTR-3B Correctly

Knowing the steps is only half the battle. Avoiding common pitfalls is equally important for seamless compliance. Here are some GSTR-1 and GSTR-3B tips for India to keep in mind.

Mistake 1: Mismatch in GSTR-1 and GSTR-3B Data: This is a major red flag for the tax department. If the tax liability you report in GSTR-3B is lower than what is calculated from your GSTR-1, the GST portal will automatically issue a notice in Form DRC-01B, demanding an explanation or payment of the difference.
Mistake 2: Incorrectly Claiming Ineligible ITC: Many businesses mistakenly claim ITC on expenses where it is not allowed, such as food and beverages, employee benefits, or motor vehicles used for personal transport. Always refer to the blocked credits list under Section 17(5) of the CGST Act to ensure you only claim what you are eligible for. You can find detailed information in our article on Blocked Credits Under Section 17(5): What ITC Cannot Be Claimed?.
Mistake 3: Ignoring Negative Values in GSTR-3B: The GSTR-3B form does not accept negative figures. If you have issued more credit notes than invoices in a month, the adjustment must be made correctly in GSTR-1 and then netted off against other liabilities in the relevant tables of GSTR-3B.
Mistake 4: Missing Filing Deadlines: Procrastination can be costly. Late filing of GSTR-1 attracts a late fee, and late filing of GSTR-3B results in both a late fee (calculated per day) and interest at 18% per annum on the outstanding tax amount.

Conclusion

The process to file GSTR-1 & GSTR-3B correctly can be summed up in a few key actions: carefully reconcile your business records, meticulously file GSTR-1 with accurate sales data, verify your GSTR-2B to claim the correct ITC, and finally, confirm your summary liability in GSTR-3B and pay your taxes on time. Consistency and accuracy in your GST filings are not just about avoiding penalties; they are crucial for maintaining a healthy compliance rating, building trust with your customers, and ensuring the smooth financial health of your business.

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Frequently Asked Questions (FAQs)

Q1. What happens if I miss the due date for GSTR-1 or GSTR-3B?

Answer: Missing the GSTR-1 due date can result in a late fee and will prevent your customers from claiming ITC on time, which can strain business relationships. Missing the GSTR-3B due date attracts both a late fee and a steep interest charge of 18% per annum on the amount of tax that was due.

Q2. Can I revise my GSTR-1 or GSTR-3B after filing?

Answer: No, neither GSTR-1 nor GSTR-3B can be revised once filed. Any corrections to an already filed GSTR-1 must be made as an amendment in the GSTR-1 of a subsequent tax period. For GSTR-3B, any adjustments for past errors can be made in the next period’s return by paying any short-paid tax with interest.

Q3. Do I need to file GSTR-1 and GSTR-3B if I had no transactions in a month?

Answer: Yes. Even if there were no sales, purchases, or any business activity during a tax period, you are still required to file a Nil Return for both GSTR-1 and GSTR-3B before their respective due dates to avoid incurring late fees and penalties.

Q4. What is the QRMP scheme?

Answer: The Quarterly Return Monthly Payment (QRMP) scheme is an option for taxpayers with an aggregate annual turnover of up to ₹5 crores. It allows them to file their main returns (GSTR-1 and GSTR-3B) on a quarterly basis, while still paying their tax liability on a monthly basis through a simple challan.

Q5. My GSTR-3B is showing a warning about a difference between tax liability in GSTR-1 and GSTR-3B. What should I do?

Answer: This warning, issued via Form DRC-01B, is a serious compliance alert. It appears when the tax liability you declared in GSTR-3B is significantly less than the liability automatically calculated from your filed GSTR-1. You must review your records immediately. You have two options: either pay the differential tax along with applicable interest or provide a valid reason for the difference in the reply section on the portal. It is crucial to address this promptly to avoid further scrutiny and potential recovery actions.

File GSTR-1 & 3B Correctly in 2025: Avoid Mistakes!