GST Return Filing 2026: GSTR-1, GSTR-3B Due Dates & Process

Goods and Services Tax (GST) return filing is a mandatory compliance requirement for every registered taxpayer in India. Whether you are a small business owner, a freelancer, or a large corporation, filing GST returns on time is crucial to avoid penalties, maintain input tax credit (ITC) eligibility, and stay compliant with the law. In this comprehensive guide, we cover all major GST returns — GSTR-1, GSTR-3B, and GSTR-9 — along with their due dates, step-by-step filing processes, late fees, and the composition scheme.

Types of GST Returns

Under the GST regime, different types of returns serve different purposes. Here are the key returns that most taxpayers need to file:

Return	Purpose	Frequency	Who Files
GSTR-1	Outward supplies (sales) details	Monthly or Quarterly	All regular taxpayers
GSTR-3B	Summary return with tax payment	Monthly or Quarterly	All regular taxpayers
GSTR-9	Annual return	Annual	Taxpayers with turnover > ₹2 crore
GSTR-4	Annual return for composition taxpayers	Annual	Composition scheme taxpayers
GSTR-5	Return for non-resident taxable persons	Monthly	Non-resident taxpayers
GSTR-6	Return for Input Service Distributors	Monthly	ISD (Input Service Distributor)
GSTR-7	TDS return under GST	Monthly	TDS deductors
GSTR-8	TCS return for e-commerce operators	Monthly	E-commerce operators

For most small and medium businesses, the key returns are GSTR-1 (outward supplies), GSTR-3B (summary return with tax payment), and GSTR-9 (annual return). This guide focuses on these three.

GST Return Due Dates 2026

Missing GST return due dates attracts late fees and interest. Here is a consolidated table of due dates for the most common returns:

Return	Frequency	Due Date	Notes
GSTR-1	Monthly	11th of next month	For taxpayers with turnover > ₹5 crore
GSTR-1 (QRMP)	Quarterly	13th of month after quarter	For taxpayers with turnover ≤ ₹5 crore
GSTR-3B	Monthly	20th of next month	For taxpayers with turnover > ₹5 crore
GSTR-3B (QRMP)	Quarterly	22nd or 24th of month after quarter	Due date depends on state (22nd for Category 1, 24th for Category 2)
GSTR-9	Annual	December 31	For previous financial year
GSTR-4	Annual	April 30	For previous financial year
IFF (Invoice Furnishing Facility)	Monthly	13th of next month	Optional for QRMP filers to upload B2B invoices monthly

Note: Due dates may be extended by the government during festivals, natural disasters, or technical issues. Always check the GST portal (gst.gov.in) or CBIC notifications for the latest due dates.

How to File GSTR-1 Step by Step

GSTR-1 is the return where you report all your outward supplies (sales) for the tax period. It includes B2B invoices (to registered buyers), B2C invoices (to unregistered buyers), credit notes, debit notes, and export invoices. Here is the step-by-step filing process:

Step 1: Login to GST Portal

1. Visit gst.gov.in and click "Login"
2. Enter your GSTIN (GST Identification Number), username, and password
3. Complete the CAPTCHA and click "Login"

Step 2: Navigate to GSTR-1

1. Go to Services → Returns → Returns Dashboard
2. Select the Financial Year and Month/Quarter
3. Click on "GSTR-1" under the returns section

Step 3: Upload Invoices

1. You can enter invoices manually one by one or bulk upload using a JSON/Excel file
2. For B2B invoices (to registered buyers): Enter the buyer's GSTIN, invoice number, date, taxable value, and GST amount
3. For B2C large invoices (inter-state supplies > ₹2.5 lakh to unregistered buyers): Enter state-wise details
4. For B2C other supplies: Enter consolidated state-wise outward supplies
5. For exports: Enter shipping bill number, date, and invoice details
6. For credit/debit notes: Enter the original invoice reference and the revised amount

Step 4: Review and Submit

1. After entering all invoices, click "Generate GSTR-1 Summary" to review the auto-generated summary
2. Verify the total taxable value, IGST, CGST, SGST, and cess amounts
3. If everything looks correct, click "Submit"
4. Once submitted, the return cannot be revised. Corrections must be made in the next period's return

Step 5: File with DSC or EVC

1. After submission, file the return using DSC (Digital Signature Certificate) or EVC (Electronic Verification Code)
2. For DSC: Ensure your DSC dongle is connected and select the authorized signatory
3. For EVC: An OTP will be sent to the registered mobile number of the authorized signatory. Enter the OTP to complete filing
4. A confirmation message and ARN (Acknowledgement Reference Number) will be generated

How to File GSTR-3B

GSTR-3B is a monthly or quarterly summary return where you declare your total outward supplies, claim input tax credit (ITC), and pay the net tax liability. Unlike GSTR-1, GSTR-3B is not an invoice-level return — it is a self-declared summary.

Key Tables in GSTR-3B

• Table 3.1 — Outward Supplies: Enter taxable value and tax amount for outward taxable supplies (other than nil-rated, exempted, and non-GST supplies), outward taxable supplies (zero-rated — exports), and other outward supplies (nil-rated, exempted).
• Table 3.2 — Inter-State Supplies to Unregistered Persons: State-wise details of inter-state B2C supplies exceeding ₹2.5 lakh.
• Table 4 — Eligible ITC: Claim ITC on inward supplies, import of goods/services, and reverse charge mechanism. ITC must be matched with GSTR-2B (auto-populated ITC statement).
• Table 5 — Exempt, Nil-Rated, and Non-GST Inward Supplies: Details of inward supplies that are exempt, nil-rated, or non-GST.
• Table 6.1 — Payment of Tax: Pay the net tax liability (output tax minus ITC) using the electronic cash ledger or electronic credit ledger.

Filing Process

1. Login to gst.gov.in and navigate to Returns Dashboard → GSTR-3B
2. Fill in each table with the required data
3. The portal auto-populates some data from GSTR-1 and GSTR-2B. Verify and adjust as needed
4. Click "Save GSTR-3B" after filling all tables
5. Click "Preview" to download a draft PDF for review
6. Click "Submit" to lock the return (cannot be changed after submission)
7. Pay the tax liability via challan using the electronic cash ledger or credit ledger
8. File the return with DSC or EVC

Late Fees and Interest

Late filing of GST returns attracts both late fees and interest. Here are the current provisions:

Return	Late Fee per Day	Maximum Late Fee	Interest
GSTR-1	₹50 (₹20 for nil return)	₹5,000	Not applicable
GSTR-3B	₹50 (₹20 for nil return)	₹5,000	18% p.a. on net tax liability
GSTR-9	₹200 per day (₹100 CGST + ₹100 SGST)	0.5% of turnover	Not applicable

Interest on Late Payment

Interest at 18% per annum is charged on the net tax liability from the day after the due date until the date of actual payment. For example, if your GSTR-3B tax liability for March 2026 is ₹1,00,000 and you file it on April 25 (5 days late), the interest will be:

Additionally, if there is a tax liability that you did not pay, interest at 24% per annum is charged for the period of non-payment.

Annual Return GSTR-9

GSTR-9 is the annual return that consolidates all monthly or quarterly returns filed during a financial year. It is a reconciliation statement that helps the government verify the accuracy of your monthly filings.

Who Needs to File GSTR-9?

• All regular taxpayers with aggregate turnover exceeding ₹2 crore in a financial year
• Taxpayers who opted for the composition scheme during any part of the year
• Taxpayers who have cancelled their GST registration during the year

Exemptions: Input Service Distributors (ISD), casual taxable persons, non-resident taxable persons, and taxpayers paying tax under TDS/TCS provisions are not required to file GSTR-9.

GSTR-9 Structure

GSTR-9 has 6 main parts:

• Part I: Basic details — GSTIN, legal name, trade name
• Part II: Details of inward and outward supplies declared during the financial year
• Part III: Details of ITC declared during the financial year
• Part IV: Details of tax paid during the financial year
• Part V: Particulars of transactions for the previous financial year declared in returns of April to September of current FY (or up to the date of filing, whichever is earlier)
• Part VI: Other information — demands, refunds, HSN summary, and late fee details

Due Date and Late Fee

GSTR-9 for a financial year is due by December 31 of the following year. The late fee for delayed filing is ₹200 per day (₹100 CGST + ₹100 SGST), subject to a maximum of 0.5% of the turnover in the state or union territory.

Composition Scheme Returns

The Composition Scheme is a simplified tax scheme for small businesses with annual turnover up to ₹1.5 crore (₹75 lakh for special category states). Under this scheme, taxpayers pay a fixed percentage of their turnover as tax and file simplified returns.

Composition Scheme Tax Rates

Type of Business	Tax Rate
Manufacturers (other than specified goods)	1% (0.5% CGST + 0.5% SGST)
Restaurant services (not serving alcohol)	5% (2.5% CGST + 2.5% SGST)
Other eligible services	6% (3% CGST + 3% SGST)
Traders and other suppliers	1% (0.5% CGST + 0.5% SGST)

Returns for Composition Taxpayers

• GSTR-4: Annual return due by April 30 of the following financial year. It consolidates all quarterly tax payments.
• CMP-08: Quarterly statement-cum-challan for payment of self-assessed tax. Due by the 18th of the month following the quarter.

Restrictions: Composition taxpayers cannot collect GST from their buyers, cannot claim input tax credit, cannot make inter-state supplies, and cannot supply through e-commerce operators.