Verify GST Number Online
Instantly check if a GST number is valid. Verifies format, state code, PAN, and check digit to catch typos and fake numbers.
Want the registered business name, status, and address? Use our GST Number Search — it shows live registry details for any GSTIN.
What is a GSTIN?
A GSTIN (Goods and Services Tax Identification Number) is a unique 15-character alphanumeric code assigned to every business registered under India's GST regime. Every taxpayer — whether a sole proprietor, partnership, company, or LLP — receives a GSTIN upon registration with the GST portal.
The GSTIN is printed on every GST invoice, and is required for filing returns, claiming input tax credit, and inter-state trade. Verifying a GSTIN before doing business ensures you're dealing with a legitimate, registered taxpayer.
How to Read a GSTIN — Structure Breakdown
Every GSTIN follows a fixed 15-character structure. Here's what each part means:
| Position | Characters | Meaning | Example |
|---|---|---|---|
| 1–2 | 2 digits | State / UT code | 27 (Maharashtra) |
| 3–12 | 10 characters | PAN of the business | AABCU9603R |
| 13 | 1 alphanumeric | Entity number (for multiple registrations in the same state) | 1 |
| 14 | Letter Z | Reserved (always Z) | Z |
| 15 | 1 alphanumeric | Check digit (catches typos) | N |
What Does This Validator Check?
Our GSTIN validator performs four checks on every GST number you enter:
- Format check — Confirms the GSTIN is exactly 15 characters with the correct pattern (digits, letters, and Z in position 14).
- State code validation — Verifies that positions 1–2 are a valid Indian state or union territory code (01 to 38).
- PAN structure — Checks that positions 3–12 follow the standard PAN format (5 letters, 4 digits, 1 letter).
- Check digit verification — The last character is mathematically derived from the first 14. If it doesn't match, the number likely has a typo or is fabricated.
This is an offline structural validation. It confirms the GSTIN is well-formed, but does not check whether it's actively registered. For registration status, use the official GST portal.
Why Verify a GST Number?
Verifying a vendor's GSTIN is critical before:
- Claiming input tax credit (ITC) — ITC claims against invalid GSTINs are rejected during assessment.
- Filing GSTR-1 / GSTR-3B — Incorrect GSTINs in your returns trigger mismatches and notices.
- Onboarding new vendors — A quick GSTIN check prevents fraud and ensures the vendor is GST-compliant.
- Processing invoices — Bulk invoice processing requires valid GSTINs for each line item.
Related Tools
- GST Number Search — see the registered business name, status, and address for any GSTIN (live registry lookup)
- GST Search by PAN — find every GSTIN registered under a PAN across India
- GST State Code List — find any state or UT code used in GSTIN
- GST Calculator — add or remove GST with CGST/SGST/IGST breakdown
Processing GST Invoices?
If you're manually copying GSTIN, amounts, and tax data from invoices into Excel, our invoice reader does it in seconds. Upload a PDF, get a structured Excel file.
Convert to ExcelFrequently Asked Questions
What is a GSTIN and how many digits does it have?
GSTIN (Goods and Services Tax Identification Number) is a unique 15-character alphanumeric code assigned to every registered GST taxpayer in India. It consists of: 2-digit state code, 10-character PAN, 1-digit entity number, the letter Z, and a checksum character.
How do I verify if a GST number is valid?
Enter the 15-character GST number in the validator above. It checks the format structure, verifies the state code (01–38), validates the embedded PAN pattern, and confirms the Luhn mod-36 checksum. For official business details (name, address, filing status), check the GST portal at services.gst.gov.in.
What does each part of a GSTIN mean?
Characters 1–2: State/UT code (e.g., 27 = Maharashtra, 07 = Delhi). Characters 3–12: PAN of the business. Character 13: Entity number (1–9 or A–Z) for multiple registrations in the same state. Character 14: Always 'Z' (reserved). Character 15: Checksum digit calculated using Luhn mod-36 algorithm.
Can I find business details from a GSTIN?
This validator checks the GSTIN format and structure offline. To see the registered business name, status, type, and address, use our GST Number Search (live registry lookup). You can also search the GSTIN on the official GST portal.
Can I validate multiple GSTINs at once?
Yes. Use the bulk validator on this page — paste a list (one per line, or comma/space separated) and it checks them all instantly, flagging valid, check-digit typo, and malformed numbers. It runs entirely in your browser, so nothing is uploaded.
Does a valid GSTIN format mean the GST number is active?
No. A valid format and correct check digit only confirm the GSTIN is well-formed and not a typo — not that the registration is currently active. A GSTIN can be structurally valid but cancelled or suspended. Check live status via GST Number Search or the official portal.
Is this GSTIN validator free?
Yes, completely free with no signup required. You can validate unlimited GST numbers, one at a time or in bulk. The tool runs entirely in your browser — no data is sent to any server.
Is there a sample or dummy GST number I can test with?
A well-formed example is 27AABCU9603R1ZN — valid state code (27, Maharashtra), a PAN-pattern body, and a correct Luhn mod-36 check digit, so this validator marks it Valid. Handy as a dummy GSTIN for testing a form field. It is a structural sample only, not a real business — for live registration status use GST Number Search or the official portal.
How is the GSTIN check digit calculated?
The 15th character is a checksum of the first 14, computed with the Luhn mod-36 algorithm: digits 0–9 and letters A–Z map to 0–35, each character is weighted alternately by 2 and 1, each product is reduced (⌊value/36⌋ + value mod 36) and summed, and the check digit is the one that makes the total a multiple of 36. A mismatch means a typo or a fabricated number. This validator runs exactly that check.