Service Overview
For most regular taxpayers, GST return filing means two returns every month: GSTR-1 by the 11th (your sales) and GSTR-3B by the 20th (a summary of sales, claimed input tax credit and the tax you pay). Businesses on the QRMP scheme file quarterly instead, but still pay tax every month.
This page shows the schedule, the portal steps, how late fees and interest are calculated, and the rules on input tax credit (ITC) that decide how much you pay.
Key Takeaways
Monthly filers: GSTR-1 on the 11th, GSTR-3B on the 20th of the following month. QRMP filers: GSTR-1 on the 13th and GSTR-3B on the 22nd or 24th after the quarter ends.
GSTR-1 is your sales statement. GSTR-3B is the summary return where you pay the tax.
The late fee is ₹50 a day for a return with liability and ₹20 a day for a nil return, up to a cap tied to turnover. Interest at 18% a year is charged separately on tax paid late.
ITC is allowed only against invoices that appear in your GSTR-2B. Reconcile your purchase books against it before you file.
Even a nil return is mandatory. Missing it still carries the late fee.
Which GST Returns You File
Your return calendar depends on how you are registered and your turnover.
| Taxpayer type |
Returns |
Frequency |
| Regular taxpayer, monthly |
GSTR-1, GSTR-3B |
Monthly |
| Regular taxpayer on QRMP |
GSTR-1 (or the invoice furnishing facility, IFF), GSTR-3B |
Quarterly returns, monthly tax payment |
| Composition dealer |
GSTR-4 |
Annual (due 30 June for the previous year) |
| Regular taxpayers |
GSTR-9 annual return |
Annual, due 31 December |
If you do not yet hold a GSTIN, start with
GST Registration Online. The rest of this page assumes you are a regular taxpayer.
GSTR-1 vs GSTR-3B
People mix these up, and the confusion costs money. They do different jobs.
| Point |
GSTR-1 |
GSTR-3B |
| Purpose |
Statement of outward supplies (your sales) |
Summary return with tax payment |
| What you report |
Invoice-wise B2B sales, B2C sales, exports, credit and debit notes, HSN summary, documents issued |
Total outward supplies, ITC claimed and reversed, tax payable and paid, interest and late fee |
| Tax payment |
None |
Yes; liability is paid before filing |
| Due date (monthly) |
11th of the next month |
20th of the next month |
| Due date (QRMP) |
13th of the month after the quarter |
22nd or 24th of the month after the quarter, by state group |
| Effect on buyers |
Feeds the buyer's GSTR-2B, so it decides their ITC |
None directly |
| Correction |
Amend through a later GSTR-1 |
No revision; fix through a later GSTR-3B |
| Late fee |
₹50 a day (₹20 for nil) |
₹50 a day (₹20 for nil) |
Because GSTR-1 feeds your customers' credit, a late GSTR-1 hurts them even when you have paid your own tax. For the details of that return, see our GSTR-1 Return Filing Service.
GSTR-1 and GSTR-3B Filing Due Dates
Standard due dates for monthly and QRMP filers:
| Return |
Monthly filers |
QRMP filers |
| GSTR-1 |
11th of the next month |
13th of the month after the quarter |
| GSTR-3B |
20th of the next month |
22nd or 24th of the month after the quarter |
| Monthly tax payment (PMT-06) |
Not applicable |
25th of the month |
| GSTR-9 |
31 December for the previous financial year |
31 December for the previous financial year |
The government can extend dates by notification. For example, CBIC pushed the March 2026 GSTR-3B date to 21 April 2026. Check the GST portal before you assume the standard date applies.
GST Return Filing Process Online: Step by Step
Here is how GSTR-1 and GSTR-3B are filed on the GST portal.
Before you start
Keep these ready. Close your books for the month, and make sure your sales register and purchase register are complete.
Mobile number registered with the portal
DSC (companies and LLPs need one) or EVC for others
Complete sales register and purchase register
How to file GSTR-1
1
Open the Returns Dashboard
Log in and go to Services, then Returns, then Returns Dashboard.
2
Select period and Prepare Online
Choose the financial year and return period, then click Prepare Online under GSTR-1.
3
Enter sales invoice details
Fill the relevant tiles: B2B, B2C, exports, credit and debit notes. Add the HSN summary and the documents-issued details.
4
Generate Summary and preview
Click Generate Summary, check the totals against your sales register, and preview the draft.
5
File with DSC or EVC
Note the ARN and keep the acknowledgement.
How to file GSTR-3B
1
Open GSTR-3B
From the same dashboard, open GSTR-3B for the period and click Prepare Online.
2
Review outward supplies
The figures are drawn from your filed GSTR-1, and you will not be able to change them in GSTR-3B itself.
3
Compare ITC with GSTR-2B
Open the ITC table and compare it with your GSTR-2B. Reverse anything ineligible.
4
Check interest and late fee
Check the interest and late-fee entries, if any.
5
Make the payment
Pay the liability through the cash ledger and, where allowed, the credit ledger. Create a challan if the cash balance is short.
6
Submit and file
File with DSC or EVC, then download the filed return.
QRMP filers: add one step. Pay tax every month through Form PMT-06 by the 25th, using either the fixed-sum or the self-assessment method.
ITC Claim in GST Return Filing: Rules and Reconciliation
Input tax credit is the tax you paid on purchases, set against the tax you owe on sales. It is also where most notices begin. These are the conditions you need to meet, drawn from Section 16 of the CGST Act and the rules under it.
You hold a valid tax invoice or debit note.
You received the goods or services.
Your supplier reported the invoice in their GSTR-1 or IFF, so it shows in your GSTR-2B.
The supplier has actually paid the tax to the government.
You have filed your own GSTR-3B for the period.
You claim within the time limit: by 30 November following the end of the financial year to which the invoice belongs, or the date you file your annual return, whichever comes first.
You pay the supplier within 180 days of the invoice date. If you do not, you reverse the credit, with interest.
Rule 36(4) caps your claim at what appears in GSTR-2B, so a missing invoice means a missing credit. Some credits are blocked altogether under Section 17(5), and your adviser can confirm which apply to you.
A monthly reconciliation routine that works
1
After your GSTR-2B for the month is generated (it appears around the 14th), match it against your purchase register line by line.
2
List invoices you hold but cannot see in GSTR-2B and chase those suppliers before the 20th.
3
Park ineligible items instead of claiming them.
4
Claim credit only in the month it is eligible. A claim made too early invites interest on the excess.
5
Do a fuller reconciliation before 30 November each year, since that is when the window for last year's credits closes.
If you claim more ITC than you are entitled to, interest runs at 24% a year on the excess under Section 50(3), plus possible penalty. Claiming less is safer than claiming and reversing.
GST Return Filing Charges, Late Fee and Interest
The portal charges no fee to file a return. What you pay for is lateness, and two charges apply.
Late fee (Section 47)
| Return type |
Per day |
Split |
| Return with tax liability |
₹50 |
₹25 CGST + ₹25 SGST |
| Nil return |
₹20 |
₹10 CGST + ₹10 SGST |
The fee stops at a cap. For GSTR-3B and GSTR-1, the caps notified by the government depend on your annual turnover: ₹2,000 up to ₹1.5 crore, ₹5,000 for ₹1.5 crore to ₹5 crore, and ₹10,000 above ₹5 crore, with ₹500 for nil returns. Sources differ on these slabs, so confirm them against the latest notification on the CBIC site.
Interest
Tax paid after the due date attracts 18% a year on the net tax paid late, counted from the day after the due date until payment. From the January 2026 tax period, the portal computes this interest on GSTR-3B for you, after netting your cash ledger balance, and the system figure cannot be reduced.
Worked example
Your GSTR-3B for August 2026 was due on 20 September 2026 and you file on 30 September. That is 10 days late.
- Late fee: 10 days × ₹50 = ₹500 (₹250 CGST + ₹250 SGST)
- Interest, if ₹1,00,000 of net cash tax was unpaid for those 10 days: ₹1,00,000 × 18% × 10 ÷ 365 = about ₹493
The practical lesson from the 2026 change is that cash deposited before the due date reduces interest even if the return itself is late. That does not remove the late fee.
Consequences beyond the fee
You cannot file GSTR-1 if your GSTR-3B for the earlier periods remains unfiled, under the rules.
E-way bill generation can be restricted for persistent defaulters.
A regular taxpayer who has not filed returns for six consecutive months can face cancellation proceedings. If your business has already stopped, speak to us about GST Cancellation Service, because closing the registration properly is far cheaper than letting returns pile up.
Rule Changes That Affect Your Filing Now
Industry notes on the recent portal changes point to three things:
GSTR-3B can no longer be filed more than three years after its original due date, a limit that began with the July 2025 tax period.
Outward supply figures in GSTR-3B now flow from GSTR-1 and are locked, so errors have to be fixed at the GSTR-1 stage.
The interest computation described above began with the January 2026 period.
Check the CBIC site and the portal's announcements for notifications that came after this page was written.
Frequently Asked Questions
Got questions? Find clear answers from our legal advisory team:
Yes. A nil GSTR-1 and GSTR-3B must be filed by the due dates, and a miss attracts the ₹20 a day late fee.
GSTR-1. Your outward supply figures in GSTR-3B come from it, and the portal expects GSTR-1 to be filed for the period.
You cannot revise a filed GSTR-3B. Adjust the error in the next period's return, with interest where it applies.
No. Costs arise only from late fees, interest and any professional you hire.
File on time anyway. This avoids the late fee, while interest runs only on the unpaid tax.
Eligibility depends on your turnover in the previous year and your return history. Check the current conditions on the portal.
Credit for invoices of the previous financial year is generally lost. Plan the last reconciliation well before that date.
Get Your GST Returns Filed with LegalDev India
Missed returns compound: the late fee grows daily, interest accrues, buyers lose credit, and the registration itself comes under threat. The LegalDev India GST Compliance Team has processed more than 10,000 GST registrations and amendments across India. We keep your calendar, reconcile your purchase books against GSTR-2B, file GSTR-1 and GSTR-3B, and handle notices if they arrive.
If you run a small business and want assisted GST return filing without hiring in-house accounts staff, send us your GSTIN and the periods you want covered. We will confirm your filing category and any pending dues before we start. Begin at LegalDev India.