GST registration: who needs it, thresholds and the step-by-step process

GST registration is one of the first compliance questions every growing business faces. Register too late and you risk penalties and lost input credit; register without needing to and you take on filing obligations you could have avoided. This guide walks through exactly how to decide, who must register no matter what, the documents you need, the step-by-step portal process, and what changes the day your GSTIN is issued.

What GST registration actually is

GST registration gives your business a unique 15-digit Goods and Services Tax Identification Number (GSTIN) tied to your PAN and state. Once registered you are legally recognised as a supplier of goods or services, authorised to collect GST from customers, pass on input tax credit, and required to file periodic returns. It is state-specific: if you operate from premises in more than one state, you need a separate registration in each.

The turnover thresholds

For most businesses supplying goods, GST registration becomes mandatory once aggregate annual turnover crosses Rs 40 lakh (Rs 20 lakh in special-category states). For service providers the common threshold is Rs 20 lakh (Rs 10 lakh in special-category states). “Aggregate turnover” means all taxable, exempt, export and inter-state supplies under the same PAN across India — not just one branch. These limits are the usual trigger, but they are not the whole story.

When registration is compulsory regardless of turnover

Several situations make GST registration mandatory from your very first rupee of sales, with no threshold benefit at all:

• You make inter-state taxable supplies of goods.
• You sell through e-commerce platforms that collect TCS (Amazon, Flipkart, Meesho and similar).
• You are liable to pay tax under reverse charge.
• You are a casual taxable person (e.g. an exhibition stall) or a non-resident taxable person.
• You act as an agent, input service distributor, or supply on behalf of another taxable person.

If any of these apply, the turnover thresholds above are irrelevant — you must register before you start supplying.

Documents you will need

Keep your PAN, Aadhaar, a recent photograph, proof of business address (rent agreement plus a utility bill and an NOC, or ownership proof), bank account details (a cancelled cheque or statement) and your business constitution documents ready. For a company or LLP you will also need the incorporation certificate and authorised-signatory board resolution. Having these in order before you start makes the application quick and avoids portal rejections.

The step-by-step process

1. Part A: On the GST portal, submit your PAN, mobile and email to receive and verify OTPs, generating a Temporary Reference Number (TRN).
2. Part B: Log in with the TRN and fill business details, promoters/partners, the principal and additional places of business, goods/services (HSN/SAC) and bank details.
3. Upload documents in the prescribed formats and sizes.
4. Authenticate via Aadhaar (faster) or submit with DSC/EVC. Aadhaar authentication can reduce the chance of physical verification.
5. Processing & GSTIN: the officer reviews the application; on approval you receive your GSTIN and registration certificate (Form REG-06).

Most clean applications are approved within a few working days. Where Aadhaar authentication is not completed, the department may order physical verification of premises, which adds time.

Regular scheme vs Composition scheme

Small taxpayers can opt for the Composition scheme, which trades input credit for a low flat tax rate and simpler quarterly payment. It suits small traders, manufacturers and restaurants below the prescribed turnover limit who sell mostly to end consumers. If your buyers need input credit, the regular scheme is usually better. We help you model both before you choose.

What changes after you register

Once registered you must charge GST on taxable supplies, issue GST-compliant invoices, file periodic returns (GSTR-1 by the 11th and GSTR-3B by the 20th, or under QRMP if turnover is up to Rs 5 crore), and maintain proper records. Filing is mandatory even for a month with no sales — a nil return is still due, and late filing attracts a fee of Rs 50 per day (Rs 20 for nil) plus 18% annual interest on unpaid tax. Voluntary registration can make sense if your buyers want input credit, but only take it on when you are ready for the ongoing filings.

A quick example

Suppose a Jaipur-based trader sells goods worth Rs 35 lakh locally — below the Rs 40 lakh goods threshold, so no mandatory registration yet. But the moment they accept an order from a buyer in Gujarat (an inter-state supply), registration becomes compulsory before that sale, regardless of turnover. Many businesses miss this trigger and end up paying tax and penalty out of pocket because they could not collect GST after the fact.

Common mistakes to avoid

• Treating the turnover threshold as the only trigger and missing the compulsory-registration cases.
• Registering in only one state when you have stock or premises in several.
• Choosing Composition when your buyers need input credit (or vice versa).
• Forgetting that nil returns are still mandatory once registered.

Voluntary registration: is it worth it?

You can register for GST even before crossing a threshold, and many small businesses do. The upside: you can issue tax invoices, claim input credit on your own purchases, and — crucially — sell to larger B2B buyers who insist on a GSTIN so they can claim credit. The downside: once registered you must file every return on time (including nil returns), charge GST that may make you pricier to end consumers, and maintain proper records. If most of your customers are GST-registered businesses, voluntary registration usually pays off; if you sell mainly to consumers below the threshold, it may simply add compliance.

Tracking your application: ARN and status

After submission you receive an Application Reference Number (ARN), which lets you track status on the GST portal. Typical statuses include “Pending for Processing”, “Pending for Clarification” (the officer has raised a query you must answer in Form REG-04 within seven working days), and “Approved”. Responding to clarification promptly and accurately is the single biggest factor in getting approved without delay. If a query is missed, the application can be rejected and you must start again.

Multi-state and multi-branch businesses

GST is state-specific, so a business with a place of business in more than one state needs a separate registration in each state, even under the same PAN. Within a single state, multiple branches normally operate under one registration with additional places of business added to it, though separate registrations for distinct business verticals are possible. Getting this structure right at the outset avoids the headache of input credit stranded in the wrong state.

Once you have your GSTIN, the work shifts to accurate monthly filing and input-credit reconciliation — the part where most penalties actually arise. Our GST registration service gets you registered correctly, and our GST returns & compliance service keeps you filed and reconciled afterwards. For related reading, see our guides on input tax credit and the latest GST rate changes.

This article is general information, not tax or legal advice. Rules can change; confirm specifics for your business before acting.