Applicability of GST — Who Needs to Register and When


Not every business needs a GST registration on day one. Whether GST applies to you depends on your turnover, the nature of your supply, and certain special categories defined under the CGST Act. This guide breaks down exactly when GST becomes applicable, with clear thresholds and real-world examples.

What Triggers GST Applicability

GST applicability is governed primarily by Section 22, 23 and 24 of the CGST Act. Broadly, applicability can be triggered in three different ways: crossing a turnover threshold, falling into a category requiring mandatory registration regardless of turnover, or choosing to register voluntarily.

Turnover-Based Threshold Limits

Registration under GST is generally triggered once your 'aggregate turnover' in a financial year crosses a prescribed limit:

•      Supplier of goods: ₹40 lakh (₹20 lakh in special category states such as most North-Eastern and hill states)

•      Supplier of services (or mixed supplier): ₹20 lakh (₹10 lakh in special category states)

•      Aggregate turnover is computed PAN-wide, across all states, and includes taxable, exempt, and export supplies — it does not exclude exempt turnover the way many people assume

•      States had the option to choose either the ₹40 lakh or the older ₹20 lakh threshold for goods, so it's worth double-checking your specific state's applicable limit

Mandatory Registration — Irrespective of Turnover

Certain categories of persons must register under GST even if their turnover is below the threshold (Section 24):

•      Persons making any inter-state taxable supply of goods (services generally retain the threshold benefit for inter-state supply, with some exceptions)

•      Casual taxable persons making taxable supply, and non-resident taxable persons

•      Persons required to pay tax under reverse charge

•      E-commerce operators, and (in most cases) persons supplying goods/services through an e-commerce platform

•      Input Service Distributors (ISD), even if not making any outward taxable supply

•      Persons required to deduct TDS or collect TCS under GST

•      Agents supplying goods or services on behalf of another registered taxable person

•      Persons supplying online information and database access or retrieval (OIDAR) services from outside India to unregistered persons in India

Voluntary Registration

Even if you're below the threshold, you may register voluntarily. This lets you claim Input Tax Credit and gives your business a more formal standing when dealing with GST-registered buyers who prefer to deal only with registered vendors (to claim their own ITC). Once you register voluntarily, you are treated like any other registered person and must comply with the full set of regular GST obligations — filing returns, issuing tax invoices, and so on.

Persons Exempt from Registration

•      Persons engaged exclusively in supplying goods or services that are wholly exempt from tax, or wholly non-taxable under GST

•      Agriculturists, to the extent of supply of produce out of cultivation of land

•      Persons whose aggregate turnover is below the applicable threshold and who do not fall in any mandatory-registration category

💡  Illustration — Threshold vs Mandatory Category

A furniture maker in Delhi with an annual turnover of ₹35 lakh, selling only within Delhi, is not required to register since he is below the ₹40 lakh goods threshold. However, the moment he starts selling the same furniture through an online marketplace like Amazon, he must register for GST immediately — regardless of turnover — because e-commerce sellers generally don't get the threshold exemption.

💡  Illustration — Services Threshold

A freelance graphic designer working from Pune, providing design services to clients across multiple states, has an annual turnover of ₹18 lakh. Since this is a service and inter-state supply of services (unlike goods) doesn't automatically force registration, and the turnover is below the ₹20 lakh service threshold, she is not required to register — though she may choose to register voluntarily to claim ITC on her software subscriptions and equipment.

⚠  Common Mistakes to Avoid

•  Calculating turnover branch-wise instead of PAN-wide — aggregate turnover must include all branches and states under the same PAN

•  Assuming any inter-state supply automatically requires registration — for services, the threshold exemption is often still available even for inter-state supply

•  Ignoring reverse charge liability because turnover is low — RCM liability triggers mandatory registration regardless of turnover

•  Not registering while selling on e-commerce platforms, assuming the usual threshold exemption applies to online sellers too

Frequently Asked Questions

Q1. Do all businesses need GST registration?

A. No. Only businesses that cross the applicable turnover threshold, or fall under a mandatory-registration category listed in Section 24, need to register.

Q2. Is GST registration state-wise or nationwide?

A. Registration is state-wise. If you operate from more than one state, you generally need a separate GSTIN for each state, though all are linked to the same PAN.

Q3. What happens if I don't register despite being liable?

A. You become liable to a penalty of 10% of the tax due (minimum ₹10,000), or 100% of the tax due if the non-registration is found to be a deliberate attempt to evade tax, apart from being made to pay the tax with interest.

Q4. Does inter-state supply of services also require mandatory registration?

A. Generally no — the threshold exemption typically remains available for inter-state supply of services, unlike goods, though certain notified categories of services are still subject to mandatory registration rules.

Q5. Can I run a business without GST registration if I stay below the threshold?

A. Yes, as long as you don't fall into any of the mandatory-registration categories under Section 24, you can legally operate without registering, though you also cannot charge GST or claim ITC.

Q6. How is 'aggregate turnover' actually calculated?

A. It is the total value of all taxable supplies, exempt supplies, exports, and inter-state supplies of a person having the same PAN, computed on an all-India basis, excluding taxes charged under GST itself and the value of inward supplies on which tax is payable under reverse charge.

✓  Key Takeaways

•  GST registration is triggered by turnover thresholds (₹40 lakh/₹20 lakh for goods, ₹20 lakh/₹10 lakh for services) or by falling into a mandatory category

•  Aggregate turnover is calculated PAN-wide, not branch-wise or state-wise

•  Certain categories (e-commerce sellers, RCM-liable persons, casual taxable persons) must register regardless of turnover

•  Voluntary registration is allowed and can be useful for claiming ITC and building credibility with B2B buyers

Note: GST rates, thresholds and procedures are revised periodically by the GST Council and CBIC. This article reflects the position understood as of the GST 2.0 rate structure (effective 22 September 2025). Please verify current figures on www.gst.gov.in or with a qualified tax professional before making compliance decisions.

Disclaimer

This content is shared strictly for general information and knowledge purposes only. Readers should independently verify the information from reliable sources. It is not intended to provide legal, professional, or advisory guidance. The author and the organisation disclaim all liability arising from the use of this content. The material has been prepared with the assistance of AI tools.