How to Do a GST Return: Step-by-Step Guide to GSTR-1 and GSTR-3B

GST return types: 13 ·
GSTR-1 due date (monthly): 11th of following month ·
GSTR-3B due date (monthly): 20th of following month ·
Late filing penalty: ₹50 per day (₹20 for nil return)

Eight numbers drive most GST filing decisions, and one pattern stands out: the official process hinges on two monthly deadlines — the 11th for sales reporting and the 20th for tax payment.

How to file GST return at home?

All filing happens on the official GST portal (gst.gov.in), and the portal’s own user guide lays out the routine: log in, open Services, select Returns, and open the Returns Dashboard, then pick the relevant financial year and tax period (GST Portal GSTR-3B guide, official portal instructions).

From there, the steps split by form:

1. Choose the return. Select GSTR-1 to report outward supplies, or GSTR-3B to declare the summary liability and tax paid (GST Portal GSTR-3B guide, official portal instructions).
2. Fill GSTR-1. Enter or upload B2B invoices, B2C supplies, exports, credit notes, debit notes, and other outward-supply categories; the data can be prepared online or with the portal’s offline utility (GST Portal user guide, official filing documentation).
3. Generate the GSTR-1 summary. Preview the figures, check the validation and error-correction results, then submit with a digital signature or electronic verification code (GST Portal user guide, official filing documentation).
4. Open GSTR-3B. Declare outward taxable supplies, reverse-charge supplies, input tax credit, exempt or nil-rated supplies, tax payable, and tax paid (GST Portal GSTR-3B guide, official portal instructions).
5. Reconcile before submitting. Check GSTR-3B figures against books of account, sales data, purchase records, and the available GSTR-2B input-tax-credit information (ClearTax, specialist tax-filing platform).
6. Pay the tax. Settle the liability from the electronic cash ledger and the eligible electronic credit ledger (GST Portal GSTR-3B guide, official portal instructions).
7. Preview, confirm, and file. Confirm the declaration and submit GSTR-3B with a digital signature or electronic verification code (GST Portal GSTR-3B guide, official portal instructions).

Quarterly filers under the QRMP scheme follow the same path on different dates: quarterly GSTR-1 is due on the 13th of the month after the quarter, and quarterly GSTR-3B is due on the 22nd or 24th depending on the state or Union Territory (GST Portal user guide, official filing documentation; ClearTax, specialist tax-filing platform).

What this means: the portal checks the data you give it, but it cannot check the data you left out. The two minutes spent comparing GSTR-2B with purchase invoices cost less than a rejected credit or a late-fee notice.

The implication: the two-minute window between uploading purchase data and filing the return is where the real compliance habit lives.

What is GSTR 1 and 2 and 3B?

• GSTR-1 — the outward-supply return: invoice-level and summary details of taxable sales, exports, credit notes, debit notes, and applicable HSN information (GST Portal user guide, official filing documentation).
• GSTR-2A and GSTR-2B — auto-drafted purchase views the system builds from vendors’ filings; they verify the credit you claim rather than being filed by you (ClearTax, specialist tax-filing platform).
• GSTR-3B — the summary return: outward taxable supplies, reverse-charge supplies, input tax credit, exempt or nil-rated supplies, tax payable, and tax paid (GST Portal GSTR-3B guide, official portal instructions).

In the filing routine, GSTR-1 speaks for your sales, GSTR-2A records what your vendors say they sold to you, and GSTR-3B is where the tax position turns into payment or credit.

What is GSTR-3B with an example?

• GSTR-3B is a single-summary declaration built from details you report in GSTR-1.
• It captures the liability side — sales, reverse charge, tax payable — and the credit side — input tax credit claimed.
• It is also the return that moves money, because tax paid through the cash and credit ledgers is declared here (GST Portal GSTR-3B guide, official portal instructions).

Example: assume a taxpayer reports total sales of ₹10 lakh and eligible input tax credit of ₹2 lakh in a month. At an 18% rate, the output tax on those sales is ₹1.8 lakh, so the ₹2 lakh credit covers the liability in the summary return. GSTR-3B would show the sales, the credit, and a net payable position that reflects the set-off.

The pattern: GSTR-1 says what you sold, GSTR-2A records what vendors say they sold to you, and GSTR-3B is where the tax position turns into payment or credit.

How do I get my GST refund?

Refund applications move through the portal’s RFD-01 process. The common routes are refund of excess input tax credit, refund on exports, and refund arising from an inverted duty structure, where the tax rate on inputs is higher than the rate on outputs.

The refund process is designed to be completed within 90 days from the date of application, and the refund lands only after the underlying GST returns are filed. The documents that speed things up: sales and purchase invoices, bank account details, and proof of export where applicable.

• File the underlying GST returns on time before applying for a refund.
• Keep invoices, bank statements, and export documentation ready for RFD-01.
• Track the refund application status on the GST portal after submission.

Why this matters: a refund is your own input tax credit coming back, not a windfall. Treat the application like a return: document everything, file on time, and expect verification.

What are the three types of GST?

• CGST (Central GST) — levied by the central government on intra-state sales.
• SGST (State GST) — levied by the state government on intra-state sales.
• IGST (Integrated GST) — levied on inter-state sales.

An intra-state sale carries both CGST and SGST; an inter-state sale carries IGST only. The three components exist so the central and state governments each receive a defined share of the tax collected.

Registered businesses collect GST from customers and remit it to the government through the electronic ledgers when they file GSTR-3B (GST Portal GSTR-3B guide, official portal instructions).

Who pays GST?

• The end consumer bears the GST included in the price of goods and services.
• Registered businesses are the collection point: they charge GST on sales, claim input tax credit on purchases, and pay the net amount to the government.
• Businesses above the registration threshold — ₹40 lakh for goods, ₹20 lakh for services — are required to register and collect GST.

So both pay in different currencies: consumers carry the cost, and businesses carry the compliance burden.

The trade-off: businesses act as the tax department’s collection arm. The money always belonged to the consumer, but the filing burden, late fees, and reconciliation work land entirely on the business.

How is GST calculated?

• Standard GST slabs: 5%, 12%, 18%, and 28%, with some essential items at 0%.
• Formula: GST amount = taxable value × applicable rate ÷ 100.

A rupee example: a ₹1,000 item at 18% carries ₹180 of GST, so the invoice total becomes ₹1,180.

What is 40% GST?

• 40% is not a standard GST slab in India.
• The standard slabs are 5%, 12%, 18%, and 28%.

When “40% GST” shows up in a message or invoice, it is usually a misreading of the top rate band — not a standard rate the GST return forms use.

Which items are 5% GST?

• Essential items such as packaged food and footwear under ₹1,000 fall in the 5% slab.
• Other goods and services fall in the 12%, 18%, or 28% slabs.

To calculate, find the slab for the product or service, apply the rate to the taxable value, and add the result to the invoice.

What this means: most invoice math is a slab lookup, not a calculation puzzle. The confusion starts when a non-standard figure like 40% circulates, so confirm the slab before you compute — and before you file GSTR-3B, because the liability you declare is the liability you owe.

What’s confirmed and what’s still unclear

The signal: the fixed part of GST — forms, due dates, late fees — is well documented. The variable part is policy and verification. For a filer, that leaves one controllable habit: file on time with reconciled purchase data, because refund speed and rate changes are outside your hands.

What the experts say

“GST return is a document containing details of income that a taxpayer must file with the tax authorities.”

— GST Portal user guide, official filing documentation

“GSTR-3B remains a key monthly return for timely tax payment.”

— ClearTax, specialist tax-filing platform

“GSTR-3B figures should be reconciled with books of account, sales data, purchase records, and available GSTR-2B input-tax-credit information before submission.”

— ClearTax, specialist tax-filing platform

The pattern: official guidance defines the forms; tax specialists keep returning to the same warning — the filing itself is easy, the reconciliation behind it is the real work.

Filing a GST return is a rhythm, not an event: report sales in GSTR-1 by the 11th, then declare liability and pay in GSTR-3B by the 20th, with purchase data checked against GSTR-2B in between. For a small-business owner filing on their own, the choice is clear — build a monthly reconciliation habit, or face ₹50-a-day late fees and credit mismatches that cost far more than the hour of bookkeeping you were trying to save.

Related reading

• How to Do a GST Return: Step-by-Step Guide for 2025
• How to Do a GST Return: NZ IRD Guide, Costs & Penalties

The pattern: linked guides extend the same filing logic to different jurisdictions, but the core rule — reconcile before you remit — stays the same.

Frequently asked questions

For the taxpayer, the recurring answer behind most of these questions is the same: a monthly reconciliation habit avoids late fees and credit mismatches that stretch beyond the 20th.