GST verification is the process of confirming whether a 15-digit GSTIN is genuine, currently active, and registered to the business that is claiming it, by checking it against the official GST Network (GSTN) portal. The check is free, takes under a minute on the consumer portal, and is the cheapest fraud control any Indian business has against shell-vendor invoices.
This is also the cheapest input-tax-credit (ITC) protection. An invoice from a cancelled or suspended GSTIN is not eligible for ITC; paying that invoice means losing the tax credit and creating a reconciliation problem at every quarterly filing. Marketplaces, lenders, and B2B platforms run GST checks at scale specifically to keep ITC clean and fraud out.
What GST Verification Is (and Why It Matters in 2026)
The 15-digit GSTIN is supposed to identify a real, registered, currently-compliant business. The verification check confirms each of those three claims. A genuine GSTIN belongs to a real entity registered with the GST Network. A currently-active GSTIN is filing returns; a cancelled or suspended one has dropped out of the compliance loop. Matching the claimed business name to the registered legal name catches the impersonation case where someone uses a different company’s GSTIN on a forged invoice.
Four use cases drive most of the verification volume in India:
- ITC claim integrity: only invoices from active GSTINs qualify for input tax credit.
- B2B invoice integrity: confirming the supplier is who they say they are before transferring funds.
- Fraud prevention against shell entities: the most common pattern in vendor-onboarding fraud is a real PAN paired with a cancelled or fake GSTIN.
- Regulatory compliance for high-value B2B onboarding: marketplace seller verification, bank vendor due diligence, lending to MSMEs.
GSTIN Structure: What Every Digit Means
Before hitting the portal, knowing the format catches the obviously-malformed GSTINs that fraudsters sometimes try.
A GSTIN is 15 alphanumeric characters with a fixed structure, as documented across major Indian compliance references:
| Digits | What it is | Example |
|---|---|---|
| 1-2 | State code (per Indian census codes) | 27 = Maharashtra, 29 = Karnataka, 07 = Delhi |
| 3-12 | Entity PAN (10 characters) | The same PAN used elsewhere by the entity |
| 13 | Entity number (multiple registrations under same PAN) | 1, 2, 3… up to Z |
| 14 | Default character | Always “Z” |
| 15 | Check digit (alphanumeric) | Calculated from the first 14 characters |
A malformed GSTIN fails one of these positional rules. A 16-digit string is not a GSTIN; a string with letters in positions 1-2 (where state codes go) is not a GSTIN; a string where positions 3-12 do not form a valid PAN is not a GSTIN. A simple format check catches these before a portal lookup.
Multiple GSTINs under one PAN
A single PAN can have multiple GSTINs. Each state of registration gets its own GSTIN (because GST is administered state-wise), and a single entity operating across states will have one GSTIN per state. A business with branches in Maharashtra, Karnataka, and Delhi has three different GSTINs against one PAN.
This matters operationally. The vendor’s HQ GSTIN may be different from the GSTIN they invoice you from. If the invoice comes from a Karnataka warehouse but the GSTIN you have on file is the Maharashtra HQ, the ITC claim will fail. The fix: verify the GSTIN that appears on the actual invoice, not just the one in the vendor master.
How to Verify a GST Number on the GST Portal
The free, 5-step consumer flow.
Verifying via gst.gov.in (step by step)
- Open gst.gov.in in any browser.
- From the top menu, choose “Search Taxpayer” then “Search by GSTIN/UIN.”
- Enter the 15-digit GSTIN.
- Solve the captcha and click “Search.”
- The portal returns the legal name, trade name, status, registration date, principal place of business state, and jurisdiction.
What you see on the result page: the registered business’s legal name and trade name (which may differ if the entity uses a brand name), the GSTIN status (Active, Cancelled, Suspended, or Inactive), the date of GST registration, and the jurisdictional officer.
What you do not see: full address (privacy by design), turnover band, individual director or partner names, or contact details. The GST portal is built for verification, not for due-diligence data extraction.
Search by PAN: when you do not have the GSTIN
The “Search by PAN” flow lets you find every GSTIN registered against a single PAN. This is the quickest way to confirm whether a vendor whose PAN you have actually has GST registrations and in which states.
The flow: same portal, choose “Search by PAN,” enter the 10-character PAN, solve the captcha, and the portal returns the list of associated GSTINs across states with each one’s status.
Reading the GSTIN status
The status field is the most important output of any GST verification check.
Active: the business is registered, has not been cancelled or suspended, and is filing GST returns. ITC claims against an Active GSTIN’s invoices are valid.
Cancelled: the GST registration has been cancelled, either voluntarily by the business or by the department for non-compliance. ITC claims against a Cancelled GSTIN are not valid for the post-cancellation period.
Suspended: registration is temporarily suspended, often for compliance gaps such as missed return filings or under departmental investigation. Treat as non-Active for ITC purposes; payments to a Suspended GSTIN should be flagged for review.
Inactive: registration completed but the business has not started filing returns. Rare; usually a brand-new registration that has not yet had its first filing cycle.
Operationally, only Active GSTINs should clear automatically in a vendor-payment workflow. Cancelled, Suspended, and Inactive should route to a manual-review queue.
GST Verification at Scale: The API Path
Manual portal lookups work for one or two checks. Marketplaces, lenders, and B2B platforms verify hundreds or thousands of GSTINs in a sitting; portal lookups do not scale.
Why marketplaces and lenders run GST checks at scale
Four use cases drive almost all enterprise GST verification volume:
- Marketplace seller onboarding: every new seller’s GSTIN is verified before listing goes live, with periodic re-verification to catch cancellations. The drop-off problem when this is manual is severe; sellers abandon onboarding flows that take more than a day.
- Lender vendor due diligence: working-capital lending to MSMEs uses GSTIN status plus return-filing recency as creditworthiness signals. A seller whose GSTIN was active when they applied but cancelled by the time the loan disburses is a red flag.
- Logistics partner onboarding: carrier and warehouse GSTIN verification before assignment, especially for ITC-sensitive freight invoicing.
- B2B SaaS subscription onboarding: capturing the right state-specific GSTIN for invoice generation and downstream e-invoicing.
Know Your Business workflows wrap GST verification alongside PAN and bank-account verification in a single onboarding orchestration.
How a GST verification API works
Input: GSTIN (and optionally PAN for cross-check). The API call hits the GSTN backend, returns a structured response with the same data the portal returns, plus return-filing recency in some implementations.
Typical response payload: legal name, trade name, status, registration date, jurisdiction, last-filed return period for GSTR-3B and GSTR-1. Sub-second SLA at scale on modern API providers.
Bulk verification: 1,000+ GSTINs at once
The use case is month-end vendor reconciliation, marketplace catalog refresh, or pre-disbursement loan-portfolio scrubs. Async or batch API patterns handle this: submit a CSV of GSTINs, receive a webhook or polling endpoint with the structured results.
Operational tip: rotate calls evenly across business hours to avoid GSTN portal rate limits. The portal has maintenance windows on the 11th to 13th of each month (return-filing peak load); batch verifications scheduled outside those windows complete cleanly.
Failure modes and fallback design
Three failure patterns to design around:
Stale data. The GSTN portal occasionally lags actual filings by 24 to 48 hours, especially around quarter-end. A GSTIN that filed its return yesterday may show as overdue today.
Government portal downtime. The 11th to 13th of every month is the peak return-filing window; the portal is slower and occasionally unavailable. Schedule bulk verifications outside those windows.
Retry logic with exponential backoff, plus PII masking in logs (the GSTIN itself is sensitive personal data of the entity). Synchronous and webhook-driven patterns both work; the right choice depends on how quickly downstream systems need the result.
GST Verification in KYB Onboarding Workflows
The vertical-specific use cases where GST verification sits inside a larger orchestration.
Marketplace seller onboarding
The seller-onboarding sequence at most major Indian marketplaces:
- PAN capture and verification.
- GSTIN capture and verification (against the PAN).
- Bank account verification with bank account verification checks that confirm the account belongs to the entity.
- Business address verification.
- Seller activation.
Cancelled or suspended GSTINs that fraudsters re-cycle are a real signal here. A GSTIN registered three years ago, cancelled six months later, and now showing up on a new seller’s onboarding application is a high-risk pattern. The fix is automated: every GSTIN goes through verification at the moment of capture, with cancelled or suspended statuses blocking the onboarding flow.
Vendor onboarding for B2B procurement
The vendor-master cleanup use case. Most large enterprises have legacy vendor masters with hundreds of GSTINs that have not been re-verified since the original onboarding. Periodic re-verification (quarterly is the recommendation across most compliance teams) catches the long tail of GSTINs that have lapsed since.
This integrates with corporate KYC requirements and the KYB document framework regulated entities apply to high-value vendor relationships. AML and sanctions screening run alongside GST verification for high-value vendors.
Lending and working-capital underwriting
GST verification plus return-filing recency is one of the strongest credit signals for MSME lending. A business that has been GST-registered for two years and is current on GSTR-3B filings is a meaningfully different credit risk from one that has missed three quarterly filings in a row.
The data trail (GSTR-3B and GSTR-1, where the borrower has authorised data sharing) feeds into the lender’s underwriting model alongside bank statement OCR outputs. The combination of GST data and bank-statement data is now standard practice across MSME-focused NBFCs and banks following the RBI KYC master direction.
Logistics and fleet partner onboarding
Last-mile delivery partners and warehousing providers, especially those handling tax-invoiced freight. GSTIN status flips during the contract are an operational risk; periodic re-verification (monthly or quarterly) is the answer. RC verification sits alongside GST in fleet partner onboarding.
How to Report a Fake GSTIN
If verification surfaces a GSTIN that looks fake or appears on an invoice the issuer cannot back up, the GST portal has a complaint flow.
The official report-fake-GSTIN flow
- Open gst.gov.in and authenticate with Aadhaar OTP.
- Navigate to the complaint or grievance module under “Services.”
- Choose the “Report a Fake GST” or equivalent option.
- Fill in the alleged fake GSTIN, the reason for suspicion, and supporting evidence (the invoice in question, delivery proof, communication records).
- Submit and note the complaint reference number.
Alternative channels: the jurisdictional GST officer (whose details are visible on a GSTIN’s portal record), the CBEC Mitra helpdesk, and the askGST_GoI Twitter handle for visible-but-not-actionable cases.
What happens after you report
The department reviews the complaint, typically within a defined time window. Possible outcomes: the GSTIN is suspended pending investigation, the issuer is asked to corroborate, action is taken against the issuer if the fraud is confirmed (cancellation plus penalty plus prosecution in serious cases).
Keep the original evidence. The reporter is sometimes asked to corroborate during the department review, and timestamps on the original communication are useful for the record.
For broader procurement-side controls, bank account verification API and the related types of bank account verification and best bank account verification provider give the parallel control surface for confirming the recipient bank account belongs to the verified entity. The combination of GSTIN verification plus account verification catches more vendor fraud than either alone.
For the underlying invoice-format requirements that make GST verification matter, Rule 46 of the CGST Rules sets out the mandatory fields a GST-compliant tax invoice must contain.
See How It Works
HyperVerge’s Know Your Business stack verifies GSTINs in bulk alongside PAN, bank account, and AML checks for marketplace and B2B onboarding. Talk to our team to see how the KYC process and the digital KYC flow integrate GST verification end to end. Book a demo.
FAQs
How can I verify a GST number online?
Open gst.gov.in, choose “Search Taxpayer” then “Search by GSTIN/UIN,” enter the 15-digit GSTIN, solve the captcha, and click search. The portal returns the legal name, trade name, registration status, registration date, and jurisdictional officer. The check is free and takes under a minute.
Is GST number verification free?
Yes, on the official GST portal at gst.gov.in. There is no charge for individual lookups via the consumer portal. Bulk or API-based verification (for marketplaces, lenders, and B2B platforms verifying hundreds of GSTINs at scale) is paid through service providers, because of the throughput, SLA, and bulk-handling features.
What is the format of a GSTIN?
A GSTIN is a 15-digit alphanumeric code: digits 1-2 are the state code, digits 3-12 are the entity’s PAN, digit 13 is the entity number (for multiple registrations under one PAN), digit 14 is “Z” by default, and digit 15 is a check character. Anything that does not match this structure is malformed.
Can I check GST registration by PAN?
Yes. The GST portal’s “Search by PAN” option lets you find every GSTIN registered against a 10-character PAN. The result shows each GSTIN with its status and state. This is useful when you have a vendor’s PAN but need to confirm their state-specific GSTINs.
How do I report a fake GSTIN?
Sign in to gst.gov.in with Aadhaar OTP, navigate to the grievance module, choose the report-fake-GST option, fill in the alleged fake GSTIN with supporting evidence (invoice, delivery proof), and submit. Alternative channels include the jurisdictional GST officer, the CBEC Mitra helpdesk, and the askGST_GoI Twitter handle.
What is the difference between GSTIN and UIN?
GSTIN is the 15-digit identifier for GST-registered businesses. UIN (Unique Identification Number) is a separate identifier issued to specialised entities like UN bodies, embassies, and certain notified persons that do not pay GST but need to claim refunds. Both are looked up through the same GST portal search.
Can a single business have multiple GSTINs?
Yes. GST is administered state-wise, so a business operating across states gets one GSTIN per state. A company with offices in Maharashtra, Karnataka, and Delhi has three GSTINs against the same PAN. Each is independent for filing and ITC purposes.
How long does GST verification take?
A manual portal lookup takes under a minute. An API verification call returns sub-second at scale. Bulk verifications (1,000+ GSTINs through batch APIs) typically complete within minutes if the GSTN portal is responsive; the timing depends mostly on the portal’s load rather than the API provider.
