How to Check GST Number Validity Online with Step-by-Step Guide, Rules, Format, and Verification Tips

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by

Himanshu
in ,

The Goods and Services Tax (GST) identification system is one of India’s biggest reforms for indirect taxation. Every business that crosses the prescribed turnover threshold must register under GST and receive a unique 15-digit GSTIN (Goods and Services Tax Identification Number).

Verifying the authenticity of a GST number is extremely important for businesses, accountants, suppliers, buyers, freelancers, transporters, and consultants. A single mismatch or incorrect GSTIN can lead to issues such as ITC denial, invoice rejection, non-compliance penalties, or mismatch during monthly GST return filing (GSTR-1 and GSTR-3B).

This guide provides a complete explanation of how to check GST number validity online, the structure of the GSTIN, mistakes people commonly make during verification, and important compliance tips.

What Is a GSTIN (GST Number)?

A GSTIN is a 15-character alphanumeric code assigned to every registered taxpayer in India.

It helps identify:

  • The State or Union Territory
  • The PAN of the business
  • The type of taxpayer
  • The registration count

GSTIN is mandatory on all tax invoices, e-invoices, credit notes, debit notes, e-way bills, and GST returns.

GST Number Format Explained (Breakdown of 15 Digits)

To verify a GST number, you first need to understand how it is structured.

Table: GSTIN Structure Explanation

Digit PositionMeaning
1st & 2nd DigitState Code (01–36)
3rd to 12th DigitPAN Number of Business
13th DigitEntity Number (registration count for same PAN in state)
14th DigitDefault alphabet “Z”
15th DigitChecksum for validation

Example of Valid GSTIN Format

29ABCDE1234F1Z5

Understanding this format helps identify fake or invalid GST numbers easily.

Why Checking GST Number Validity Is Important

Many small and medium businesses depend on GST compliance to claim Input Tax Credit (ITC). Any error in GSTIN can delay ITC claims or cause mismatching in GSTR-2A/2B.

Major Benefits of Verifying GSTIN

  1. Ensures supplier authenticity
  2. Prevents fake invoice fraud
  3. Reduces risk of ITC rejection
  4. Helps avoid duplicate registrations
  5. Protects buyers from non-compliant vendors
  6. Helps identify cancelled or inactive GSTINs
  7. Useful during audits and scrutiny
  8. Reduces chances of penalties

How to Check GST Number Validity Online

You can verify GSTIN in two main ways:

  1. Through official online portals
  2. Through invoice cross-verification and GSTIN structure check

Below is a detailed guide.

Step-by-Step Guide to Verify GST Number Online

Although the verification screen may change over time, the GST number authentication process follows a standard pattern.

Step 1: Visit the official GST verification page

You can search for “GST number verification India” or “GSTIN status check” in your browser.

Step 2: Locate the GSTIN search option

Look for options such as:

  • Search Taxpayer
  • Search GSTIN/UIN
  • Verify GST Number

Step 3: Enter the 15-digit GSTIN

Make sure you type the GST number accurately. Even a single wrong character can lead to “No Record Found”.

Step 4: Complete the CAPTCHA (Human Verification)

This ensures that the request is from a real user.

Step 5: View the GSTIN Details

If the GST number is correct, the system displays:

  • Legal business name
  • Trade name
  • Registration type (Regular, Composition, SEZ, etc.)
  • GST status (Active, Cancelled, Suspended)
  • Registration date
  • Nature of business activities
  • Location and jurisdiction

If GSTIN is fake or invalid, it shows “No Details Found” or “Invalid GSTIN Format”.

How to Perform Manual Verification Without Online Tools

If you don’t have internet access or want to verify quickly, you can manually analyze the GSTIN.

Manual Validation Tips

  1. Check state code
  • For example, 07 = Delhi, 27 = Maharashtra, 29 = Karnataka
  • If someone from Delhi gives GSTIN starting with 29, it is incorrect.
  1. Check PAN inside GSTIN
    Digits 3–12 match the PAN of the business.
  2. Check entity number (13th digit)
    Should be 1–9 or A–Z, representing number of registrations under the same PAN.
  3. Check 14th digit
    Should always be “Z”.
  4. Checksum validation
    The 15th digit is mathematically calculated and helps detect incorrect entries.

Common Errors While Verifying GST Numbers

Many users misread or mistype the GSTIN.

Frequent Mistakes

  • Confusing letter “O” with number “0”
  • Mixing letter “I” with number “1”
  • Wrong state code used during registration
  • PAN mismatch
  • Entering old or cancelled GSTIN
  • Typing spaces before or after the number
  • Using lowercase letters (should always be uppercase)

Incorrect GSTIN entries can block ITC claims worth thousands of rupees.

How to Identify Fake GST Numbers

Fake GST numbers usually show suspicious patterns such as:

  1. Wrong state code compared to invoice address
  2. PAN does not match business details
  3. Incorrect length (less than or more than 15 characters)
  4. No online record found
  5. Entity digit (13th character) inconsistent with business type
  6. Mismatch between GSTIN on invoice & address listed

Fake GSTIN usage can lead to serious penalties under GST law.

GST Verification Tips for Businesses and Accountants

  1. Verify GSTIN before booking any invoice
  2. Keep a monthly checklist for all supplier GSTIN
  3. Re-check GSTIN before filing GSTR-3B
  4. Maintain a master list of trusted GSTIN
  5. Re-verify if supplier changes address or business structure
  6. Avoid purchases from unregistered vendors (except small cases)
  7. Re-verify GSTIN if invoice value is unusually high
  8. Keep GSTIN validation proof in records

These practices help reduce compliance risks.

GST Number Status Types and Meaning

GSTIN may have different status indicators.

Table: GST Number Status Explained

GST StatusMeaning
ActiveGSTIN is valid and operational
CancelledGSTIN cancelled voluntarily or by department
SuspendedUnder review or pending cancellation
InactiveTemporarily disabled due to verification issues

Understanding this helps businesses avoid compliance mistakes.

Reasons Why Your GST Number May Show Invalid

  1. GST registration cancelled
  2. Incorrect entry while typing
  3. Portal temporarily unavailable
  4. GSTIN wrongly printed on supplier invoice
  5. Business migrated but not updated
  6. PAN mismatch
  7. Technical issue or duplicate state code

Consequences of Using Invalid GSTIN

Using an incorrect or fake GSTIN can cause:

  1. ITC mismatch in GSTR-2A and GSTR-2B
  2. ITC denial during filing
  3. Penalties under GST Act
  4. Scrutiny from tax department
  5. Rejection of invoices
  6. Legal dispute with suppliers
  7. Additional tax liability

Conclusion

Checking GST number validity online is a simple yet powerful step to ensure tax compliance and prevent fraudulent transactions. As businesses depend heavily on GST invoices and ITC claims, verifying GSTIN before entering invoices into books is highly recommended. By understanding the structure of GSTIN, using online verification tools, and following correctness checks, taxpayers can avoid errors, penalties, and losses during monthly GST filings.

Disclaimer

This article is only for informational and educational purposes. GST rules and portal functionalities may change over time. Always verify GST information carefully before using it for compliance, accounting, or invoice processing.