GST for online sellers, without the jargon.
Selling online in India means getting GST right: the correct HSN codes, compliant invoices, GSTIN at checkout, marketplace TCS, and returns filed on time. This guide walks through each piece, with free calculators and step-by-step help for doing it on Commmerce.
Schedule a DemoGeneral guidance for Indian online sellers, not tax advice. GST rules change and depend on your business, so confirm specifics with a qualified chartered accountant.
What GST means for your online store
GST touches almost every part of selling online, from how you tag products to how you invoice and file. These are the pieces to get right.
HSN and SAC codes
Every product needs an HSN code, and services need a SAC code. The code decides the GST rate applied.
GST invoices
Compliant invoices show your GSTIN, the customer details, HSN/SAC, and the CGST/SGST/IGST breakup.
Customer GSTIN
B2B buyers add their GSTIN at checkout to claim input tax credit on the purchase.
Marketplace TCS
Sell on a marketplace and it collects TCS on your sales, which you reclaim in your returns.
Returns and filing
Registered sellers file returns on schedule. Late filing adds a per-day fee plus interest.
The numbers
Use the free calculators below for GST amounts, TCS, and late fees instead of guessing.
HSN and SAC codes, and why they matter
An HSN code classifies a physical product and sets its GST rate; a SAC code does the same for services. Getting the code right keeps your rates and invoices correct, so it is worth doing once, properly. Find your HSN code →
What an HSN code is
A standardised number that classifies goods and maps to a GST rate. Read the explainer
Finding the right one
Match your product to its HSN code so you charge the correct GST. How to find your HSN code
Is it mandatory?
Whether you must show HSN on invoices depends on your turnover. When HSN is required
HSN vs SAC
Goods use HSN, services use SAC. See the difference
Raise GST-compliant invoices, capture GSTIN at checkout
A GST invoice needs your GSTIN, the correct tax breakup, and HSN/SAC codes. For B2B orders, letting customers add their GSTIN at checkout lets them claim input credit, which often decides whether a business buys from you.
Build a GST invoice
Generate a clean, compliant GST invoice with the CGST/SGST/IGST split. GST invoice generator
Validate a GSTIN
Check that a supplier or customer GSTIN is well-formed before you trust it. GSTIN validator
GSTIN at checkout
Let business buyers add their GSTIN when they order on your store. How it works on Commmerce
Work out the GST
Add or remove GST from a price at any rate in seconds. GST calculator
Selling on marketplaces, TCS, and staying filed
If you also sell on marketplaces, they collect TCS on your sales and deposit it with the government; you reclaim it in your GST returns. And whether you sell on your own store or a marketplace, filing returns on time avoids a per-day late fee and interest.
Estimate marketplace TCS
See how much TCS a marketplace collects on your sales so it is not a surprise. TCS calculator
Estimate a late fee
Filing a return late? Work out the fee and interest before you file. GST late fee calculator
Own store vs marketplace
On your own Commmerce store there is no marketplace TCS or commission cut, so more of each sale stays with you. Compare selling channels
Sell direct and keep margin
A branded online store lets you own the customer and the margin. Explore online store
Do the GST maths without a spreadsheet
GST Calculator
Add or remove GST from any amount at any rate.
Open tool →HSN Code Finder
Look up the HSN code and GST rate for a product.
Open tool →GST Invoice Generator
Create a compliant invoice with the tax breakup.
Open tool →GSTIN Validator
Check whether a GSTIN is well-formed.
Open tool →Marketplace TCS Calculator
Estimate TCS collected on your marketplace sales.
Open tool →GST Late Fee Calculator
Estimate the late fee and interest on a delayed return.
Open tool →GST setup, step by step
The GST-related how-tos from the Commmerce help centre.
SAC, GSTIN & checkout
Frequently asked questions
Do I need GST registration to sell online in India?
Most sellers who list on ecommerce marketplaces, and many who run their own online store, need a GST registration and GSTIN. The exact rules depend on your turnover, product type, and whether you sell across states, so confirm your specific case with a chartered accountant before you start.
What is an HSN code and do I need one?
An HSN (Harmonised System of Nomenclature) code classifies a product and determines the GST rate that applies to it. Sellers are generally required to show HSN codes on GST invoices, with the number of digits depending on turnover. You can look one up with the HSN code finder.
What is the difference between an HSN code and a SAC code?
HSN codes classify goods (physical products), while SAC codes classify services. If you sell products you use HSN codes; if you bill for services you use SAC codes. More on HSN vs SAC.
What is TCS on marketplace sales?
When you sell through an ecommerce marketplace, the marketplace collects a small percentage of your taxable sales as Tax Collected at Source (TCS) and deposits it with the government. You can claim that amount back through your GST returns. Use the TCS calculator to estimate it.
Can customers add their GSTIN at checkout on my store?
Yes. On Commmerce, customers can enter their GSTIN during checkout so their business can claim input tax credit on the purchase, which matters for B2B and bulk buyers. See how it works.
What happens if I file GST returns late?
Late filing of GST returns attracts a per-day late fee plus interest on any tax due, so returns are best filed on time even when there is no tax to pay. Use the GST late fee calculator to estimate the amount.
Sell online with GST built in.
See how Commmerce handles GST invoices, HSN codes, and GSTIN at checkout for your store.
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