GST basics for online sellers in India: registration, CGST/SGST vs IGST, and invoices

Not tax advice. GST rules change and depend on your business. This is a general overview as of 2026 — confirm how it applies to you with a chartered accountant or tax practitioner.

Do online sellers need GST registration?

GST registration is generally required once your aggregate turnover crosses the threshold for your state and supply type — the long-standing headline figures are ₹40 lakh for suppliers of goods and ₹20 lakh for services in most states, with lower limits in some special-category states.

Some sellers must register regardless of turnover. The case most online sellers meet is inter-state supply of goods: if you ship goods to buyers in other states, registration is generally compulsory. Selling through marketplaces that collect tax at source has its own rules too. Check both with your CA before you start shipping across state lines.

CGST + SGST or IGST?

For goods, the tax type depends on where the supply starts and where it is delivered (the place of supply):

• Seller and delivery address in the same state: intra-state supply, taxed as CGST + SGST (or UTGST), each half of the rate.
• Delivery address in a different state: inter-state supply, taxed as IGST at the full rate.

A worked example (18% GST, ₹1,000 taxable value)

Seller in Gujarat, buyer in Gujarat

CGST 9% = ₹90 + SGST 9% = ₹90

Intra-state

Seller in Gujarat, buyer in Maharashtra

IGST 18% = ₹180

Inter-state

The total tax is the same; what changes is which government receives it and how it is reported.

What a GST tax invoice should show

• Your name, address and GSTIN.
• A unique, consecutive invoice number and the invoice date.
• The buyer's name and address, and the buyer's GSTIN if they are registered (B2B).
• Place of supply (state).
• For each line: description, HSN code, quantity, taxable value, GST rate and tax amount.
• The tax split: CGST and SGST, or IGST.
• The invoice total.

HSN codes

HSN codes classify goods for GST. The number of HSN digits you must print on invoices depends on your turnover, and B2B invoices have stricter requirements than B2C. Find the right code and rate for each product once and record it on the product, so every invoice comes out right.

E-invoicing and e-way bills

Businesses above a turnover threshold must generate B2B invoices through the government's e-invoicing system (an IRN for each invoice), and moving goods above a value limit generally needs an e-way bill. Both have their own thresholds and exceptions — check where you stand.

What your store software should handle

On Slaby, all of the above is built in: turn on GST in settings with your seller state and GSTIN, set HSN codes and rates per product or variant (or inherit them from the category), and every order gets a GST invoice PDF the buyer can download or have emailed.

To be clear about the limits: Slaby does not generate IRN e-invoices or e-way bills and does not file GST returns. Use your accounting software or GST practitioner for those.

• Calculating CGST/SGST or IGST from the delivery state automatically.
• A GST rate and HSN code per product, and per variant where they differ.
• Freezing the tax on the order when it is placed, so later price changes never alter an issued invoice.
• Producing the invoice PDF for you and the buyer.
• Exporting orders so your accountant can file returns.

Common questions

Is GST charged on the delivery fee?

Generally, delivery charged together with the goods follows the tax treatment of the goods. How you show it on the invoice can vary, so confirm the treatment for your products with your CA.

When is IGST charged instead of CGST and SGST?

When the goods are delivered to a different state from the one you supply from. Same-state deliveries are charged CGST plus SGST.

Can a composition-scheme dealer sell online?

Composition dealers face restrictions — notably on inter-state supplies of goods and on selling through e-commerce operators — and issue a bill of supply rather than a tax invoice. Check with your CA before selling online under composition.

Does Slaby file my GST returns?

No. Slaby calculates GST on each order and produces invoices; you can export orders for your accountant, who files the returns.

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