gst guide

What is GSTIN? How to Apply for GST Registration in India

Complete guide to GSTIN — what it is, its 15-digit format, who needs to register, how to apply online, and how to use your GSTIN on invoices.

6 min readUpdated 10 Jan 2025

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What is GSTIN?

GSTIN (Goods and Services Tax Identification Number) is a unique 15-character alphanumeric code assigned to every GST-registered business in India. It is like a PAN card but specifically for GST. Every business that is required to register under GST receives a GSTIN.

Understanding the GSTIN Format

The 15-character GSTIN has a specific structure: Characters 1-2 = State code (e.g., 01 for Jammu & Kashmir, 27 for Maharashtra), Characters 3-12 = PAN of the business owner, Character 13 = Number of registrations in same state (usually 1), Character 14 = Z (default), Character 15 = Checksum digit.

Who Needs to Register for GST?

GST registration is mandatory for: (1) Businesses with aggregate annual turnover above ₹40 lakhs (goods) or ₹20 lakhs (services), (2) Those supplying goods/services in multiple states, (3) E-commerce sellers (regardless of turnover), (4) Businesses making inter-state supplies, (5) Casual taxable persons.

How to Apply for GST Registration Online

Apply at gstin.gov.in: (1) Visit GST Portal, (2) Click 'Register Now', (3) Select 'New Registration', (4) Fill Part A with PAN, mobile, and email for OTP, (5) Complete Part B with business details, address, and documents, (6) Upload documents (PAN, Aadhaar, address proof, bank statement), (7) Verify with DSC or Aadhaar OTP, (8) Submit — ARN generated in 15 minutes, GSTIN in 3-7 working days.

Frequently Asked Questions

Is GST registration free?

Yes. GST registration on the GST portal (gstin.gov.in) is completely free. You don't need to pay any government fee.

Can I use InvoiceGPT without a GSTIN?

Yes. You can create bills of supply without a GSTIN if you're not yet registered. Once you get your GSTIN, add it in Settings and it appears on all future invoices.

How long does it take to get a GSTIN?

After submitting your application online, you typically receive your GSTIN within 3-7 working days if all documents are correct.

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