GST registration is mandatory for most businesses in India once they cross the turnover threshold, and from day one for inter-state suppliers and e-commerce sellers. The good news: applying on the GST portal is free, and the whole process is online. This guide covers whether you actually need to register, the documents, the step-by-step application, and the mistakes that get applications rejected.
If you would rather hand it off, Regikart's GST registration team files it for you, including the HSN/SAC code selection that trips up most DIY applicants.
Do you actually need GST registration?
| Who | Threshold for mandatory GST |
|---|---|
| Goods suppliers | Turnover over Rs 40 lakh (Rs 20 lakh in special-category states) |
| Service providers | Turnover over Rs 20 lakh (Rs 10 lakh in special-category states) |
| Inter-state suppliers | No threshold - mandatory from day one |
| E-commerce sellers (Amazon, Flipkart, etc.) | No threshold - mandatory |
| Casual taxable persons, ISD, agents, TDS/TCS deductors | Mandatory |
You can also register voluntarily below the threshold - worth doing if you want to claim input tax credit, sell to B2B customers who require a GSTIN, or expand inter-state. Businesses supplying only exempt goods or services, and agriculturalists selling their own produce, generally do not need to register.
Fees and timeline
The government charges nothing for GST registration - the application on gst.gov.in is free. You only pay a professional fee if a CA files it for you. A clean application is usually approved in 3-7 working days; queries or mismatches can push it to 15 days or more.
Documents required
- PAN of the business (proprietor's PAN for a proprietorship; the entity's PAN otherwise).
- Aadhaar, PAN, photo and contact details of each authorised signatory / promoter.
- Proof of the principal place of business - rent agreement plus owner's NOC if rented, or an electricity bill / property tax receipt if owned (not older than two months).
- Bank account proof - a cancelled cheque or recent bank statement in the business name.
- Constitution documents - partnership deed, or Certificate of Incorporation and MOA/AOA for a company/LLP, or trust deed.
The registration process, step by step
- On gst.gov.in, go to Services and Register Now, then complete Part A - legal name (exactly as per PAN), PAN, mobile and email - and verify the OTPs.
- You receive a Temporary Reference Number (TRN), valid 15 days. Save it; you need it to complete Part B.
- Log back in with the TRN and fill Part B: business details, promoter/partner details, authorised signatory, principal place of business, bank account, and HSN/SAC codes.
- Upload the documents (PDF/JPEG, within the size limits).
- Complete Aadhaar authentication - Aadhaar e-sign (OTP) is fastest; physical/biometric verification at a GST Suvidha Kendra is the fallback.
- Submit with DSC (companies/LLPs) or e-sign (others). An Application Reference Number (ARN) is generated.
- The officer reviews within the statutory window and either issues your 15-digit GSTIN or raises a query you respond to.
HSN / SAC codes - the step that causes rejections
Selecting the wrong HSN code (for goods) or SAC code (for services) is one of the most common reasons an application is queried or rejected. Pick codes that genuinely match your activity, and add the ones you realistically use. The minimum digit-level depends on turnover.
| Turnover | Minimum HSN digits |
|---|---|
| Up to Rs 5 crore | 4 digits |
| Rs 5 - 25 crore | 6 digits |
| Above Rs 25 crore | 8 digits |
Common rejection reasons
- Business name not matching the PAN exactly.
- Aadhaar authentication failing because the Aadhaar name does not match the PAN.
- HSN/SAC codes that do not match the actual business activity.
- Address proof older than two months, or a rent agreement without the owner's NOC.
- Bank account inactive or details entered incorrectly.
- Constitution type not matching the documents uploaded.
- A director without a DIN - see our guide on DIN reactivation and KYC.
Special cases
E-commerce sellers on Amazon, Flipkart, Meesho and similar platforms must register regardless of turnover. Freelancers and consultants register once they cross Rs 20 lakh, but often register voluntarily earlier to claim ITC on laptops, software and subscriptions and to invoice corporate clients. Food businesses that cross the goods threshold need GST in addition to an FSSAI licence - we cover the full food-business stack in our cloud kitchen licensing guide.
After you get your GSTIN
- Switch your invoicing to GST-compliant invoices and update your GSTIN across your website and documents.
- File GSTR-1 (outward supplies) and GSTR-3B (summary) by their monthly or quarterly due dates, and GSTR-9 annually.
- Reconcile input tax credit each month against GSTR-2B - see our GST input tax credit reconciliation guide.
- Register for e-invoicing if your turnover crosses the e-invoicing threshold.
- Keep records for the period required under GST law.
FAQs
Is GST registration free?
Yes - the government charges no fee. You only pay a professional fee if a CA files it for you.
How long does it take?
Usually 3-7 working days for a clean application; longer if the officer raises queries.
Do I need a current account to register?
Yes, a bank account in the business name is required. A current account is standard for businesses.
Can I have multiple GSTINs on one PAN?
One GSTIN per state per PAN. If you operate in multiple states, you take a separate GSTIN in each, all under the same PAN.
What if I cross the threshold mid-year?
You have 30 days from the date you cross the threshold to apply for registration.
Is GST mandatory for Amazon/Flipkart sellers?
Yes - e-commerce sellers must register regardless of turnover.
Register with Regikart
Regikart's CAs handle the full GST registration - document checks, HSN/SAC selection, filing, Aadhaar e-sign and any officer queries - and stay on for your returns afterwards. Unsure whether your business structure affects your GST position? Our Pvt Ltd vs LLP vs OPC guide helps, or talk to a CA via our contact page.
About the author
Srishty
Senior Advisor at Regikart. Want to discuss this in the context of your business?
