GSTIN Validator – Free GST Number Format Verification

GSTIN Format Verification Tool

Instant Client-Side Check

Enter 15-Digit GSTIN Number:

Try examples:

GSTIN format appears valid.

GSTIN Structural Breakdown:

State Code (Digits 1-2) --

Entity PAN (Chars 3-12) --

Entity Number (Char 13) --

Registration count in state

Default Character (Char 14) --

Constant 'Z'

Checksum (Char 15) --

MOD-36 Algorithm

Anatomy of a 15-Digit Indian GSTIN

Under the Goods and Services Tax (GST) framework in India, every registered taxpayer receives a 15-character alphanumeric Goods and Services Tax Identification Number (GSTIN). The number is systematically constructed from five logical segments:

Characters 1–2 (State Code): A 2-digit numerical code representing the Indian State or Union Territory where the registration is held (e.g., 07 for Delhi, 27 for Maharashtra, 29 for Karnataka).
Characters 3–12 (Permanent Account Number - PAN): The 10-character PAN of the business or proprietor. The 4th character indicates the legal constitution (C = Company, P = Individual, F = Partnership/LLP, H = HUF, T = Trust).
Character 13 (Entity Number): A single digit or letter representing the number of registrations the same PAN holder possesses in that specific state (1 through 9, followed by A through Z).
Character 14 (Default Alphabet): By default, this character is permanently set to the letter 'Z'.
Character 15 (Checksum Digit): A mathematical check character calculated across the preceding 14 characters using the ISO/IEC 7064 MOD 36, 36 algorithm to detect typographical errors.

Important Note on Active Status

Responsible Verification Notice: This tool performs structural, state-code, PAN syntax, and mathematical checksum verification. It verifies that the format of the GSTIN conforms to the statutory standard. This tool does not verify whether a taxpayer is officially active or suspended on government records, as that requires live real-time access to the official GST Common Portal.

GST State Codes Reference Table

A quick reference of common state codes used in Indian GST:

Code	State / Union Territory	Code	State / Union Territory
01	Jammu & Kashmir	19	West Bengal
02	Himachal Pradesh	20	Jharkhand
03	Punjab	21	Odisha
06	Haryana	22	Chhattisgarh
07	Delhi	23	Madhya Pradesh
08	Rajasthan	24	Gujarat
09	Uttar Pradesh	27	Maharashtra
10	Bihar	29	Karnataka
18	Assam	33	Tamil Nadu

Frequently Asked Questions

It means the number satisfies all statutory formatting requirements: exactly 15 characters, valid state code prefix, genuine PAN pattern, character 14 as 'Z', and matching MOD-36 checksum logic.

Yes! Pre-checking the GSTIN format helps prevent common IRP error codes like 2151 (Invalid Recipient GSTIN) or checksum rejections when generating e-invoices.

You can use our free E-Invoice Generator to create complete multi-item tax invoices and compute intra-state and inter-state GST rates automatically.

Explore Complementary GST Utilities

Calculate taxes, generate e-invoices, and prepare schema JSON for free.

GST Calculator E-Invoice Generator E-Invoice Validator