Most businesses assume GST registration is only about crossing a turnover number — ₹40 lakh for goods, ₹20 lakh for services. That’s true for the majority of cases, but it’s only half the law. The Central Goods and Services Tax Act, 2017 defines two separate paths into GST registration: Section 22 (turnover-based) and Section 24 (compulsory, regardless of turnover). If you fall into any Section 24 category, the ₹40 lakh/₹20 lakh threshold simply does not apply to you — you’re liable from your very first rupee of taxable supply, or in some cases before you’ve supplied anything at all.
This is the question we get asked most often by businesses that assumed they were “too small” to need GST — right up until a marketplace, a client, or a GST notice told them otherwise. This page covers exactly who is a taxable person liable for GST registration under both sections, so you can check where your business actually stands.
Section 22: registration by turnover
Under Section 22, you’re liable to register once your aggregate turnover in a financial year crosses ₹40 lakh for goods or ₹20 lakh for services (₹10 lakh in a handful of special-category north-eastern and hill states — not applicable in Tamil Nadu). This is the path most businesses expect. For the full breakdown of thresholds, documents, and our fixed pricing by business type, see our GST Registration in Chennai guide.
Section 24: compulsory registration, no threshold at all
Section 24 lists specific categories of persons who must register for GST the moment they take up that activity — turnover is irrelevant. If any of the following describes your business, the ₹40 lakh/₹20 lakh threshold does not protect you from registration:
- Inter-state suppliers of goods — if you supply goods to a customer in another state, you must register regardless of turnover. (Inter-state supply of services is treated more leniently — see below.)
- Casual taxable persons — occasional suppliers with no fixed place of business in the state where they’re supplying, such as a Chennai business taking a stall at an exhibition in another state.
- Persons liable under reverse charge (RCM) — if you’re liable to pay GST on inward supplies under reverse charge (legal services, GTA freight, and other specified categories), you must register.
- Non-resident taxable persons — occasional suppliers with no fixed place of business in India.
- E-commerce sellers — anyone supplying goods through a marketplace like Amazon, Flipkart, or Meesho must register from the first sale, with no turnover threshold. This is the single most common way small Chennai sellers become liable early.
- E-commerce operators required to collect tax at source (TCS) under Section 52, and the operators of platforms like Swiggy and Zomato that pay tax on behalf of certain restaurant partners under Section 9(5).
- Persons required to deduct tax at source (TDS) under Section 51 — mainly government departments and specified bodies.
- Agents supplying on behalf of other taxable persons.
- Input Service Distributors (ISD) — a business office that receives invoices for services used across multiple branches and distributes the input tax credit to them.
- Suppliers of Online Information and Database Access or Retrieval (OIDAR) services from outside India to a person in India.
- Persons or classes notified by the government on the GST Council’s recommendation, from time to time.
The one relief worth knowing: the government has separately exempted inter-state supply of services (and specified inter-state supply of handicraft/handmade goods) from the compulsory-registration rule, up to the normal ₹20 lakh/₹40 lakh threshold. So a Chennai-based consultant or service provider taking on a client in another state does not automatically trigger compulsory registration the way a goods supplier does — the rule is genuinely stricter for goods than for services.
Why this catches growing B2B businesses specifically
Our clients are established ₹1 crore+ B2B businesses — ecommerce sellers, restaurants on Swiggy/Zomato, contractors, manufacturers and exporters, and professional practices. Several Section 24 categories map directly onto how this kind of business actually operates and expands:
- An Amazon or Flipkart seller who assumed they’d register “once sales pick up” — registration was already compulsory from day one.
- A manufacturer or exporter who starts supplying a customer in another state for the first time — that single inter-state goods supply is enough to require registration, even if total turnover is still well under ₹40 lakh.
- A contractor who wins a government tender — government departments deducting TDS under Section 51 is a Section 24 trigger on the paying side, and the contractor’s own supply obligations follow the standard rules.
- A business that starts paying a Chennai-based advocate or a GTA transporter and becomes liable to pay GST under reverse charge on that expense — registration follows even if the business itself has no outward taxable supply yet.
What it costs to get this wrong
GST liability under Section 24 starts from the date the triggering activity began — not the date you eventually notice it. If a Section 24 obligation is discovered late (say, in a department audit after you’ve been selling on a marketplace unregistered for months), you owe tax on everything supplied from that date, plus interest at 18% per year, plus a penalty that can run up to 10% of the tax due or ₹10,000, whichever is higher — considerably more if it’s treated as deliberate evasion. A voluntary, self-reported registration and disclosure is treated far more leniently than one the department catches first.
If any of the Section 24 categories above describes your business — or you’re simply not sure which side of Section 22 vs Section 24 you fall on — we’ll check it for you as part of registration, at our standard fixed pricing: ₹1,500 + GST for a sole proprietorship, ₹1,800 + GST for a partnership (up to 2 partners), and ₹2,000 + GST for a private limited company (up to 2 directors). See the full breakdown on our GST Registration in Chennai page, or our GST Registration Fees page for pricing only. Call or WhatsApp 70 9232 9232.
Frequently asked questions
Is GST registration only required after my turnover crosses ₹40 lakh?
No. Crossing ₹40 lakh (₹20 lakh for services) is one way to become liable, under Section 22. Section 24 of the CGST Act separately makes registration compulsory for certain categories of business — regardless of turnover, even ₹0. If you fall into any Section 24 category, the threshold does not apply to you at all.
I sell on Amazon or Flipkart with very low sales. Do I still need to register?
Yes. Selling goods through an e-commerce operator makes registration compulsory from your first sale under Section 24(ix), with no turnover threshold. This is the single most common way small Chennai sellers get caught off guard — the marketplace itself will not onboard you without a GSTIN, so this usually surfaces before you can sell at all.
What is a casual taxable person, and does it apply to me?
A casual taxable person is someone who occasionally supplies goods or services in a state where they have no fixed place of business — for example, a Chennai business taking a stall at a trade fair or exhibition in another state. This requires a special registration for that specific period under Section 24(ii), even if your regular Chennai business is well under the turnover threshold.
What if I only receive services under reverse charge, like legal or GTA services — do I need to register?
Yes. If you are liable to pay GST under reverse charge on any inward supply (common examples: legal services from an advocate, goods transport agency freight, or services from an unregistered supplier in specified categories), Section 24(iii) makes registration compulsory regardless of your turnover.
I supply goods to another state — does that alone trigger compulsory registration?
For goods, yes — any inter-state taxable supply of goods requires registration under Section 24(i), with no threshold. For services, the government has separately exempted inter-state supply of services (and specified inter-state supply of handicraft/handmade goods) from this compulsory-registration rule up to the normal ₹20 lakh/₹40 lakh threshold — so the rule is stricter for goods than for services.
We’re a Chennai company that has to deduct TDS or collect TCS under GST — do we need our own GST registration?
Yes. A person required to deduct tax at source under Section 51 (mainly government departments and specified bodies) or an e-commerce operator required to collect tax at source under Section 52 must both register compulsorily under Section 24, with no turnover threshold — even if the entity itself is not otherwise engaged in taxable supply.