The basic idea: registration is turnover-linked
GST registration is not automatic for every shop and freelancer in India. The law says you must register once your aggregate turnover in a financial year crosses a threshold. The commonly applicable limits have been ₹40 lakh for suppliers of goods and ₹20 lakh for suppliers of services (with lower limits of around ₹20 lakh and ₹10 lakh in certain special category states). These limits have been revised in the past, so always verify the current limit on gst.gov.in before deciding to stay unregistered.
If you are new to how GST itself works — the CGST/SGST split on local sales and IGST on inter-state sales — start with our primer on what GST is and how it is structured.
What counts as "aggregate turnover"?
This is where most small businesses miscalculate. Aggregate turnover is computed PAN-wide, all-India — not branch by branch, and not GSTIN by GSTIN. It includes:
- Taxable supplies of goods and services
- Exempt supplies (yes, even though no GST is charged on them)
- Exports and inter-state supplies to your own branches
It excludes GST itself and inward supplies on which you pay tax under reverse charge.
Example: Ramesh runs a kirana store in Pune with ₹32 lakh of taxable sales and also earns ₹10 lakh renting out an exempt agricultural warehouse. His aggregate turnover is ₹42 lakh — above the goods threshold — even though his "GST-liable" sales alone are only ₹32 lakh. He must register.
When registration is compulsory — regardless of turnover
Certain situations trigger mandatory registration from rupee one. Even a ₹5,000 transaction can pull you in. The main cases are:
- Inter-state taxable supply of goods — a Jaipur handicraft seller shipping a ₹2,000 order to Bengaluru generally needs registration (service providers got relief up to the threshold, goods sellers largely did not).
- Selling through e-commerce operators — sellers on marketplace platforms have traditionally required registration irrespective of turnover; limited relaxations exist for small intra-state sellers, so check the current position on gst.gov.in.
- Casual taxable persons — you set up a stall at a trade fair in another state for two weeks.
- Persons liable under reverse charge — if you receive services like goods transport where reverse charge applies, you need registration to pay that tax.
- Non-resident taxable persons, agents, and input service distributors.
- Persons required to deduct or collect tax — covered in our guide to GST TDS and TCS.
Quick reference: threshold vs compulsory
| Situation | Registration needed? |
|---|---|
| Local goods trader, turnover below threshold | No (optional) |
| Goods trader crossing the threshold | Yes, within 30 days of crossing |
| Service provider below the services threshold | No (optional) |
| Any inter-state supplier of goods | Yes, from the first sale |
| Seller on an e-commerce marketplace | Generally yes — verify current relaxations |
| Recipient liable under reverse charge | Yes |
| Exclusively exempt supplies (e.g. fresh produce) | No |
Voluntary registration: sometimes smart, sometimes not
You can register even below the threshold. Why would anyone volunteer for return filing? Three practical reasons:
- Your customers demand it. B2B buyers want a GST invoice so they can claim input tax credit. Without a GSTIN, corporate clients may simply not onboard you as a vendor.
- You buy a lot of taxed inputs. A registered business recovers the GST paid on purchases as credit; an unregistered one absorbs it as cost. If you spend ₹10 lakh a year on inputs taxed at 18%, that is ₹1.8 lakh of credit on the table.
- Credibility and tenders. Many government and corporate tenders require a GSTIN.
The trade-off: once registered, you must charge GST on all taxable sales and file returns every period — even nil returns. Small B2C businesses often lose price-competitiveness by registering voluntarily, so weigh it carefully. If your customers are consumers and your margins are thin, the composition scheme may be a middle path once you do register.
What happens if you should have registered but didn't?
The consequences compound quietly:
- Tax from the date you became liable — the department can demand GST on all sales made after the threshold was crossed, and you usually cannot recover it from old customers. On ₹10 lakh of post-threshold sales at 18%, that is ₹1.8 lakh out of your own pocket.
- Interest on that tax for the entire delay period.
- Penalty — the law provides a penalty for failure to register that can run into a percentage of tax due (with a minimum amount); verify current figures on gst.gov.in.
- No credit for the past — buyers cannot claim ITC on your pre-registration sales, damaging relationships.
How to actually register
Registration is free, fully online on the GST portal, and typically needs your PAN, Aadhaar, proof of place of business, and bank details. Aadhaar-authenticated applications are usually processed within about a week. Our step-by-step GST registration tutorial walks through every screen, and once you have your GSTIN, the returns overview explains what you will file and when.
Bottom line: track your aggregate turnover PAN-wide every month, remember that exempt income counts towards the limit, and treat inter-state goods sales and marketplace selling as automatic triggers. When in doubt, the 30-day window after crossing the threshold is your deadline — do not sit on it.