GSTIN (GST Identification Number)
GSTIN is the unique 15-digit number assigned to every GST-registered business in India, used for tax filings, invoicing and compliance purposes.
GSTIN stands for Goods and Services Tax Identification Number. It is the unique identification code assigned to every business or individual registered under the Goods and Services Tax (GST) regime in India. Every GSTIN corresponds to one GST registration in one state or union territory for one legal entity.
Format and Structure
A GSTIN is exactly 15 characters long and follows a defined structure that encodes meaningful information:
| Position | Characters | What It Represents |
|---|---|---|
| 1–2 | Two digits | State code (e.g., 07 = Delhi, 27 = Maharashtra, 29 = Karnataka) |
| 3–12 | Ten characters | PAN of the taxpayer (the PAN of the legal entity) |
| 13 | One digit | Entity number within the state (1 for first registration, 2 for second, etc. — relevant for businesses with multiple GST registrations in the same state) |
| 14 | One letter | Always "Z" by default |
| 15 | One character | Check digit (alphanumeric) |
Example: 27AAACT2727Q1ZS
27= MaharashtraAAACT2727Q= PAN of the entity1= First registration in the stateZ= DefaultS= Check digit
This structure means that just from a GSTIN, you can identify the state where the business is registered and the PAN of the business entity.
How to Obtain a GSTIN
GSTIN is obtained through GST registration on the GST portal (gst.gov.in). The application (Form GST REG-01) requires:
- PAN of the business entity
- Aadhaar of the proprietor/directors/partners
- Proof of business registration (Certificate of Incorporation, Partnership Deed, etc.)
- Address proof of the principal place of business
- Bank account details (cancelled cheque or bank statement)
- Digital signature or Aadhaar-based OTP authentication
Once the application is approved (typically within 3–7 working days), the applicant receives an ARN (Application Reference Number) immediately and the GSTIN after approval. A GST registration certificate (Form GST REG-06) is issued, which contains the GSTIN.
How to Verify a GSTIN
Any GSTIN can be verified — without logging in — on the GST portal at gst.gov.in under the "Search Taxpayer" option. Verification shows:
- The legal name of the registered taxpayer
- Trade name (if different)
- Registration date
- Status (Active, Suspended, Cancelled)
- Business type (Regular, Composition, etc.)
- Principal place of business address and state
This verification is important before claiming Input Tax Credit on invoices, as ITC is only available for GST charged by a registered supplier with an active, valid GSTIN.
Significance for Businesses
On invoices: GST-registered businesses must mention their GSTIN on every tax invoice issued. The recipient's GSTIN must also appear if the recipient is a registered business (B2B supply).
For Input Tax Credit: ITC can only be claimed against invoices from suppliers with a valid, active GSTIN. A GSTIN that has been suspended or cancelled means ITC on those invoices is at risk.
Multiple GSTINs: A business operating in multiple states is required to obtain a separate GSTIN in each state where it has a business presence or makes taxable supplies. All GSTINs of a single PAN are linked in the GST system.
On the website: GST-registered businesses are expected to display their GSTIN on their website, typically in the footer. This is also required by CBIC guidance and helps customers verify the registration.
GSTIN vs GSTIN ARN vs UIN
GSTIN: The final registration number, received after approval.
ARN: Application Reference Number — the acknowledgement number received immediately on submission of the registration application. Can be used to track application status before GSTIN is issued.
UIN: Unique Identification Number — a separate type of number issued to UN agencies, embassies and other specified entities that need to claim refunds on purchases but are not regular GST taxpayers.