Formula & Calculation Methodology
GSTIN structure: 2 digits (State Code) + 10 alphanumeric chars (PAN) + 1 char (Entity Number) + Z (Default) + 1 check digit. Total 15 characters.
Step-by-Step Worked Example
GSTIN to verify: 27AAAAA0000A1Z5
- 1. Verify total length = 15 characters
- 2. State Code: 27 (Maharashtra)
- 3. Embedded PAN: AAAAA0000A (Valid 10-character PAN structure)
- 4. Entity Number: 1 (First registration of this PAN in state)
- 5. Default Character: Z (Mandatory in GSTIN)
- 6. Check Digit: 5
Result: Status: Valid GSTIN Format | State: Maharashtra (27) | Holder Type: Association/Company
What is a GSTIN?
A Goods and Services Tax Identification Number (GSTIN) is a unique 15-digit alphanumeric tax identifier assigned to every registered business and enterprise in India under the Goods and Services Tax (GST) system.
15-Digit GSTIN Structural Breakdown
- First 2 Digits: State code according to the Indian Census 2011 (e.g., 27 for Maharashtra, 07 for Delhi, 29 for Karnataka, 33 for Tamil Nadu, 09 for Uttar Pradesh).
- Next 10 Characters: The Permanent Account Number (PAN) of the business owner or legal entity.
- 13th Digit: Entity number indicating the count of registrations the same PAN holder has within that state (1 through 9, then A through Z).
- 14th Character: The letter Z by default.
- 15th Character: Check digit for automated error detection.
Frequently Asked Questions
What is the structure of a GSTIN?
GSTIN has 15 digits: 2-digit state code + 10-char PAN + 1-digit entity code + Z + 1 check digit.
How can I check if a supplier GST number is real?
You can test the 15-digit structure with BharatUtility validator and cross-check real-time active filing status on the official GST portal (gst.gov.in).
Is GSTIN required for claiming Input Tax Credit (ITC)?
Yes, a valid and active 15-digit GSTIN on tax invoices is mandatory to claim Input Tax Credit under GST laws.
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