GSTR-3B Filing: Step-by-Step Guide on GST Portal The twentieth of every month is probably written in red on your calendar if your business is incorporated in India. This is the due date of GST return filing through GSTR-3B returns for most taxpayers. However, when you compare this to how you filed this return a year or two ago, the current filing of this return in 2026 is definitely different. The GST website has become increasingly automated and strict with the introduction of the IMS towards the end of 2025, as well as the "hard-locking" of data that the system generates automatically. Your data now needs to be exactly what your suppliers have submitted; you cannot just "punch in" figures to match your books.
We will walk you through every process involved in GSTR-3B filing in this in-depth tutorial, right from the most essential steps relating to Input Tax Credit and IMS. As an accountant or as an entrepreneur, attempting GSTR-3B filing for your business, you will benefit from our tutorial in complying with all rules and avoiding the new auto penalties that will apply.
GSTR-3B: What is it? It is a self-declared summary monthly return. It is a statement that shows your GST liabilities for a particular period. In simple words, it tells the government:
The amount you sold - Outward Supplies.
The amount of input tax you have paid to suppliers.
How much cash tax you really owe after deducting the credit.
GSTR 3B is a statement whereas GSTR 1 is a description consisting of every single invoice. But there is a critical improvement for 2026: You can't submit GSTR 3B on the grounds that you haven't filed GSTR 1 for the same period. There is a clear linkage established amongst both.
Who needs to file GSTR-3B? All regular GST-registered persons are obliged to file GSTR-3B. It includes:
Monthly filers: Voluntary opt-in and turnover exceeding ₹ 5 crores.
Quarterly filers ( QRMP scheme): They submit GSTR-3B on a quarterly basis. They pay taxes on a monthly basis through PMT-06.
Important: You have to submit a Nil GSTR 3B even if you have no business activity during a particular month. Otherwise, you have to pay a late fee, and in view of recent regulations from 2026, you shall not be able to file GSTR 1 and generate E-WAY Bills instantly.
Essential Steps Before You Proceed This will require that you have the following ready before logging into the GST website. Technologies like "prepare offline" are becoming less favored, as the "auto-populate" method has resulted in the "real-time online" method becoming the new normal.
GSTR-1 Filed: The GSTR-1 filing requirement is now automated and satisfied in GSTR-3B. You cannot move forward if you have not filed it.
IMS Action Completed: New in 2026: Invoice Management System (IMS) IMS will compel you to either Accept, or Reject, or Keep Pending the received invoices from the vendors. Your ITC eligible in GSTR-2B will rely on this.
Mobile number or digital signature: for EVC - OTP check.
Accounting Data: It is necessary to keep your sale and purchase statements at hand to check them regarding the GST statement. This should be managed by efficient software like the Swipe-Simple Billing & Payment App.
The New 'IMS' Requirement in the 2026 Update The Invoice Management System (IMS ) has to be taken care of prior to handling your GSTR-3B forms. ITC does not simply “appear” in your GSTR-3B towards the end of 2025. Its origin lies in your GSTR-2B, now generated because of your activities within the IMS.
Go to Invoice Management System (IMS) under Services > Returns.
A list of the invoices that your suppliers have uploaded will appear.
Act Now:
Accept: Your GSTR-2B and GSTR-3B Table 4 get the ITC.
Reject: You are no longer eligible for the ITC.
Pending: No ITC is claimed this month; the invoice is carried over to the following month.
Re-compute GSTR-2B: Click "Compute GSTR-2B" to update your draft ITC statement after making changes.
If you skip this step, the system may "Deem Accepted" all invoices, including perhaps fraudulent ones you didn't wish to claim or, depending on the default setup, "Deem Rejected," which might result in tax loss.
Detailed steps for filing GSTR-3B These are the workflows to file GSTR-3B after you have filed GSTR-1 and cleared your IMS activities.
Step 1: Sign in & explore Go to the GST Portal.
Please input your correct credentials.
Go to Dashboard, then click "Services" > "Returns" > "Returns Dashboard".
Select the Period for Filing Returns and Financial Year (e.g., January 2026).
Click on "Search
The GSTR-3B tile will now appear to you. The status "Not Filed" and the due date, generally the 20th, will then appear. "Prepare Online" must now be clicked.
Step 2: Finish the Survey (For People Who Did Not Finish It Yet) ‘Do you want to file a Nil return?’ will be appearing as the prompt.
If you have no sales, purchases, liabilities, or ITC claimed for the month, then select Yes.
For a standard return, select No. Then, click.
Step 3: Verify the Summary Provided by the System A "System Generated Summary" page will be displayed. This is the most important change in this GST taxation period.
Your GSTR-1 will automatically populate Table 3.1 (Liabilities).
Your GSTR-2B (which is obtained from IMS), automatically fills your Table 4 (ITC).
Recommendation: These fields will turn red if there is a substantial difference (usually above a difference of 10%) between your books of accounts and the auto-populated figures. While you can modify them, doing so will generate a warning, which will attract the taxation authority’s scrutiny of your GSTIN. It is always preferable to make changes in the source (GSTR-1 or IMS) instead of editing GSTR-3B .
Click "Close" in order to proceed to the main dashboard.
Step 4: Tax on Outward & Reverse Charge Inward Supplies Table 3.1 It will be clear from your computations which functions are being referred to when your responsibility
3.1(a) Your normal sales of taxable outbound supplies. (GSTR-1 auto-filled).
3.1(b) Exports and SEZ supplies are zero-rated supplies.
3.1(c) Exempt/Nil Rated: These are sales which are not subject to taxes.
3.1(d) Reverse-chargeable inward supplies: This is very crucial. If the registered suppliers have filed it, this information usually comes through GSTR-2B; otherwise, you will have to manually include RCM obligations from unregistered suppliers (such GTA services).
Ensure that the configurations on this page match with your Swipe billing software's sales register. Any mismatch here implies that you are either overpaying (loss of cash) or underpaying (risk of penalty).
Step 5: Inter-State Supplies (Unregistered/Composite) Table 3.2 Table 3.1(a) is further detailed in this table. The government uses it to transfer money between states, however, it doesn't raise your tax liability.
They are entered to provide materials to UIN holders, composition dealers, and unregistered persons in other states.
The warning might be issued by tax department officials if this form is not correctly filled out for not receiving their share of IGST.
Step 6: Table 4: ITC Eligibility (The Most Important Section) Table 4 has been subject to a lot of changes lately. Notice that it is no longer just “Net ITC .” You have to accurately state the reversals to avoid getting the “Excess ITC" warning.
4(A) ITC Available: Auto-fill through GSTR-2B. This includes RCM , All Other ITC, and Import of goods .
4(B) ITC Reversed: If applicable, you have to do this by hand.
4(B)(1) Permanent Reversal: ITC that you will never be able to claim (e.g. disallowed credits under Section 17(5), meal expenses, personal use, reversals under Rule 42/43).
4(B)(2) Temporary Reversal: The ITC that you are currently reversing but might still claim later (for example, if you haven't paid the supplier within 180 days or if the goods haven't arrived). This is crucial. If you reverse here, you will be able to recover it later in Table 4(D)(1).
4(C) Available Net ITC: This is the net of (A) less (B). The sum is credited to your Electronic Credit Ledger.
4(D) Additional Information
4(D)(1) ITC Reclaimed: Please report if you have now become eligible for ITC that you reversed in 4(B)(2) in a previous month. Note: This figure must also be added to "All Other ITC" (4(A)(5)).
Validation Check: Your Electronic Credit Reversal and Reclaimed Statement and Table 4(D)(1) are currently being checked by the portal. You will be denied the ability to submit claims unless you can offer a reason when you file more claims than you reversed before.
Step 7: Table 5: Non-GST, Nil, and Exempt Inward Supplies This is for reporting tax free purchases.
Exempt or Zero: Purchases of cereal, fresh food, etc.
Liquor for human consumption , gasoline, and diesel oil are exempt from GST.
This is important for data accuracy even if it does not have any effect on taxes.
Step 8: Interest and Late Fee Table 5.1 Late Fees: The late fee will be calculated in the following month's GSTR-3B return itself, if this return is filed late. This field will not be editable, and payment is mandatory.
Interest: Please calculate the 18% per annum rate of interest by hand and submit it to us in case you are late in paying your taxes. It is ultimately your decision that you are accountable for disclosing your tax liability, even if the software might suggest a certain amount.
Step 9: Paying tax When each table has been checked:
"Save GSTR-3B" button should be clicked. A prompt "Request saved successfully" will appear.
After scrolling down, click "Proceed to Payment".
You will be able to see the balances of both the credit and cash ledger.
The system automatically adjusts your tax liability using the available ITC (first IGST, then CGST/SGST) in order to clear the tax liability.
Create Challan: If your ITC + Cash Balance is not enough, clicking "Make Payment/Post Credit to Ledger" will generate a challan for the amount of the shortfall.
Payments can be made via UPI , NEFT /RTGS , or Net Banking.
To adjust the obligation after making a payment, press "Make Payment/Post Credit to Ledger" once again. A success message will be displayed.
Step 10: Complete Submission "Proceed to File" button needs to be clicked.
For the declaration, tick the box.
From the dropdown, pick the one labeled Authorized Signatory.
Click "File GSTR-3B with DSC" (Digital Signature) or "File GSTR-3B with EVC" (OTP via email or cellphone).
Enter the OTP by clicking on the ‘Verify’ button.
Achievement! A 'Filing Successful' notice with an ARN (Application Reference Number) will appear. For your records, download the GSTR-3B file.
Three Typical Errors to Avoid in 2026 The government has tightened the rules surrounding errors. Here are things you should be aware of:
1. Ignoring the "Hard Lock" In the old days, accountants used to adjust the automatically generated sale amounts in Table 3.1 to correspond with their accounts. Large variances in 2026 are either invalidated or lead to immediate notifications.
Fix: Make sure your GSTR-1 is 100% accurate before submitting. Use GSTR-1A (the amendment option) to correct any mistakes in your GSTR-1 before filing GSTR-3B.
2. Reversals which are misreported (Table 4B) Several taxpayers only report the "Net" amount in Table 4(A) and do not fill Table 4(B). This practice leads to inconsistencies in the Electronic Credit Reversal Statement and is now legally disallowed.
Fix: Always show the Reversals in 4(B) and the Gross ITC in 4(A). The "Gross minus Reversal" method has to be followed.
3. Paying Under the Wrong Head While preparing a challan, it is usually the case that the tax is paid under the "Cess" head instead of the "CGST" or "SGST" head.
Fix: Even before you log in to the website, you can make use of Swipe’s features to find out exactly what you owe. In a bid to transfer your cash balance in case of a mistaken payment, you are required to fill out a form known as a PMT-09.
Conclusion When GSTR-3B needs to be filed in 2026, data verification will be more in action compared to data entry. This is because the system is designed to detect irregularities very quickly because of the integration of IMS, GSTR-1, GSTR-2B, and GSTR-3B. The days of doing "adjustments" in the report are over for real-time accuracy in invoicing.
Maintain discipline when it comes to billing so that you ensure a smooth filing system. Get a technology solution that helps you keep inventory and generates GST-compliant e-invoices and automatically generated reports that meet the requirements set by the GST website. Finally, “Step by Step” filling is not a difficult reconciling problem anymore, but rather a quick 5-minute click-through process when your base data is properly prepared.
Next Step: Access the GST website to view your 'Electronic Credit Reversal and Reclaimed Statement' now. It might be difficult for you to reclaim the temporary ITC credits this month if the opening balance has been mistakenly recorded for the last year.
FAQs 1. Can I revise a filed GSTR-3B on the GST Portal? You cannot modify a GSTR-3B already filed. You should rectify any data entry errors in the next month's return or use the GSTR-1A to modify the sales returns prior to the filing of the GSTR-3B.
2. How does the Invoice Management System (IMS) affect GSTR-3B? It is compulsory to claim credit through IMS, and you will have to “Accept” the supplier’s invoices in order for them to appear in GSTR-2B. Failure to perform any action in IMS could lead to erroneous claims of Input Tax Credit (ITC).
3. What is the GSTR-3B late fee and interest penalty? Late fees of ₹50 per day (₹20 for Nil GSTR-3B). The fees shall be capped in terms of turnover. Moreover, you shall be required to pay an 18% interest per annum on the outstanding taxes from the day succeeding the due date.