GSTIN (Goods and Services Tax Identification Number)

A GSTIN (Goods and Services Tax Identification Number) is a 15-character alphanumeric number assigned to each taxpayer registered under India's Goods and Services Tax. A business with registrations in several states has a separate GSTIN for each.

Why it matters

The GSTIN appears on tax invoices, e-way bills and returns, and it lets buyers claim input tax credit and authorities match transactions. Billing software and marketplaces validate it when onboarding sellers. Because the structure encodes the state and PAN, it also reveals where and under whom the business is registered.

Example

27ABCDE1234F1Z5

1. 27: two-digit state code.
2. ABCDE1234F: the holder's PAN.
3. 1: entity number within that PAN in the state.
4. Z: a default character.
5. 5: a check character computed from the others.

A pattern check can catch typos, and a checksum or portal lookup confirms more. The GST system's public search shows whether a GSTIN is active.

Common mistakes

• Assuming one GSTIN per company. Each state registration has its own.
• Validating only the length and not the checksum.
• Using a cancelled or suspended GSTIN on invoices without checking its status.

Rules and thresholds vary by country and change over time; this entry is a definition only, not tax advice.

Related

• GST
• PAN card
• HSN code
• Invoice

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