GST

GST Registration in India: Who Needs It and How to Apply (2026)

22 February 2026 • 6 min read • By CA Regi Tom Antony FCA

Goods and Services Tax has been India's most consequential indirect-tax reform since independence. Whether you're a freelancer crossing Rs20 lakh or a manufacturer selling across states, GST registration is often the first compliance milestone after incorporation. This guide explains exactly when you must register and how to do it cleanly.

1. Who must register for GST?

GST registration is mandatory in the following cases:

Threshold turnover: Rs40 lakh for goods (Rs20 lakh in special-category states), Rs20 lakh for services (Rs10 lakh in special-category states)
Inter-state supply: Any registration required from rupee one, regardless of turnover
E-commerce sellers: Selling through Amazon, Flipkart, Zomato — mandatory regardless of turnover
Casual taxable persons and non-residents: Mandatory before commencing supply
Reverse Charge cases: If you receive notified supplies subject to RCM
Voluntary: Even below threshold, you may register to claim ITC and supply to GST-registered B2B customers

2. Choosing the right registration type

Regular taxpayer

Charges GST at applicable rate (typically 5%, 12%, 18% or 28%), claims input tax credit, files GSTR-1 and GSTR-3B monthly (or quarterly under QRMP if turnover < Rs5Cr).

Composition scheme

Available to small businesses below Rs1.5Cr (Rs50L for services). Pay a flat rate (1% trader, 5% restaurant, 6% services) on turnover without ITC. No inter-state supply, no e-commerce sales.

3. Documents required

PAN of business / proprietor
Aadhaar of proprietor / authorised signatory
Certificate of Incorporation / Partnership Deed
Bank account proof — cancelled cheque or statement
Registered office proof — utility bill plus rent agreement / ownership proof
Digital Signature Certificate (companies and LLPs)
Photograph of authorised signatory

4. The REG-01 application process

Registration is done on gst.gov.in via Form GST REG-01:

Part A: PAN, mobile, email → OTP verification → TRN (Temporary Reference Number)
Part B: Business details, promoter / partner KYC, principal place of business, goods / services, bank account, verification with DSC or EVC
ARN (Application Reference Number) generated immediately
Aadhaar authentication (where opted) speeds up processing to 7 days; without it, physical verification may follow

5. Timeline

With Aadhaar authentication: GSTIN typically issued within 7 working days. Without Aadhaar (or if flagged for verification): up to 30 days, with possible queries via REG-03 to which you must respond within 7 days via REG-04.

6. Post-registration obligations

Display GSTIN prominently at place of business
Issue GST-compliant tax invoices with HSN / SAC codes
Monthly GSTR-1 (10th) and GSTR-3B (20th); quarterly under QRMP if turnover < Rs5Cr
Annual GSTR-9 (and GSTR-9C if turnover > Rs5Cr) by 31 December
E-invoicing if turnover > Rs5Cr
Maintain books and records for 6 years

7. Penalties for non-registration

If you're liable to register but don't, the penalty is 10% of tax due (minimum Rs10,000), and in cases of wilful default, up to 100% of tax due plus interest at 18% p.a. and potential prosecution.

Conclusion

GST registration is a 7-day affair when documents are in order. The harder part is what comes after — clean invoicing, accurate ITC, monthly returns and reconciliation. If you'd like a CA-led GST setup with ongoing filing, our retainer starts at Rs3,999/month.