GSTIN Validator
Is this GST number well-formed? Every one of its 15 characters, explained.
Paste a GSTIN to check its State code, PAN, entity number and check character. Nothing is sent anywhere.
Did you mean
Character by character
| Position | Part | Value | Result | What it means |
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Is it registered and active?
This page checks the format only. The GST portal shows the legal name, status and registration date: copy the GSTIN, open Search Taxpayer → Search by GSTIN/UIN, paste it and type the captcha.
Results
| Line | GSTIN and note | Result | State |
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Tax rules and rates change. This calculator follows the rules described on this page and may not cover every situation. Check the official source or a qualified tax professional before filing or invoicing.
About the GSTIN Validator
A GSTIN (Goods and Services Tax Identification Number) is the 15-character number every GST-registered business in India prints on its invoices. Its structure is fixed: a two-digit State code, the holder’s PAN, an entity number, a default “Z” and a check character calculated from the other fourteen. A wrong GSTIN on an invoice can cost the buyer their input tax credit, so it is worth checking before you bill a customer or pay a supplier.
Paste one GSTIN to see what each character means and whether the check character matches, or paste a whole list — from a spreadsheet, a vendor master or an invoice register — to check them all at once and download the results. The check runs entirely in your browser and uses no data from the GST portal, so it tells you whether a number is well-formed, not whether it is registered: for that, use the official Search Taxpayer page linked from the results.
How to use it
- Paste or type a GSTIN — spaces, hyphens and lower case are fine.
- Read the result and the breakdown: State, PAN and holder type, entity number, the “Z” and the check character. If the check fails, the tool shows which character it expects and, for common slips such as the letter O for a zero, the corrected GSTIN.
- To check many, paste one per line or several separated by commas (rows copied from a spreadsheet work too: every 15-character code on a line is picked out). Filter to the invalid ones, copy the valid ones, or download the full report as CSV.
- For registration status, legal name and filing history, open the GST portal’s Search Taxpayer page and enter the GSTIN there.
Examples
29ABCPE1234F1Z7
Valid structure · Karnataka (29) · PAN ABCPE1234F, holder type P: individual · registration 1 · check character 7
29ABCPE1234F1Z8
Invalid: the check character should be “7”, not “8”
29ABCPEI234F1Z7
Invalid: characters 3–12 are not a PAN · suggested correction: 29ABCPE1234F1Z7
Look-alike slips — a letter O or I where a digit belongs, a digit where a letter belongs, or two neighbours swapped across them — are tried automatically, and a correction is offered only when it makes the whole GSTIN valid. A plain wrong check character gets no guess: any of the first 14 characters could be the wrong one.
Common uses
- Check a customer’s GSTIN before raising a tax invoice, so their input tax credit is not lost to a typo.
- Clean up a vendor or customer master: paste the GSTIN column, filter the invalid ones, download the report.
- Read a GSTIN at a glance: which State, whose PAN, what kind of entity.
- Spot look-alike typos (O for 0, I for 1) in GSTINs copied from scanned invoices.
How a GSTIN is built
- 1–2: State code of the registration, from the Census 2011 codes GSTN uses — 27 for Maharashtra, 29 for Karnataka, 07 for Delhi, 33 for Tamil Nadu. 97 is “Other Territory” and 99 is used for suppliers outside India. Code 28 (undivided Andhra Pradesh) is not used: GSTINs in Andhra Pradesh start with 37 and in Telangana with 36.
- 3–12: PAN of the business or person, the same 10 characters as on the PAN card. One PAN can have a GSTIN in every State where it is registered.
- 13: entity number — 1 for the first registration of that PAN in the State, then 2 to 9 and A to Z, so one PAN can hold up to 35 registrations in a State (for example separate business verticals).
- 14: “Z” by default.
- 15: check character, calculated from the first 14 characters, so most single typos and swapped neighbours are caught.
The structure follows the registration certificate in Form GST REG-06 issued under rule 10 of the CGST Rules, 2017.
How the check character is calculated
The check is a Luhn algorithm in base 36:
- Give each character a value: 0–9 for the digits and 10–35 for A–Z.
- From the left, multiply the values alternately by 1 and 2.
- For each product, add the quotient and the remainder of dividing it by 36, and add these up.
- The check value is (36 − total mod 36) mod 36, written back as a character (0–9, A–Z).
For 27AAPFU0939F1Z the result is V, so 27AAPFU0939F1ZV is consistent. The algorithm detects any single wrong character and most swaps of two neighbours, but it cannot tell a real GSTIN from a made-up one with a correct check character.
PAN holder types (the PAN’s 4th character)
- P individual · C company · H Hindu undivided family · F firm or LLP · A association of persons · T trust · B body of individuals · L local authority · J artificial juridical person · G government agency
The 5th character of the PAN is the first letter of the holder’s name (for individuals, of the surname). The PAN’s last letter is its own check letter; the Income Tax Department does not publish how it is calculated, so it cannot be verified offline.
GSTINs without a PAN
Some registrations are not PAN-based: UIN holders such as UN bodies and foreign embassies, non-resident taxable persons, overseas suppliers of online services, and tax deductors registered with a TAN. For these the tool checks the State code, the length and the check character, and marks them as special registrations.
Limitations
- An offline structure check only: it cannot say whether a GSTIN is registered, active, suspended or cancelled, or whose name it is in. Use the GST portal’s Search Taxpayer page for that.
- A made-up GSTIN with a correct check character passes; the PAN’s own check letter cannot be verified offline.
- Special registrations without a PAN are only checked for the State code, length and check character.
- Up to 10,000 lines at a time; the table shows the first 500 and the CSV report has them all.
Privacy
Everything is checked in your browser. The GSTINs you paste are never uploaded, stored or sent to the GST portal.
Frequently asked questions
Does “valid structure” mean the GSTIN is registered?
No. It means the number is well-formed and its check character is consistent. A cancelled GSTIN, or a made-up one with the right check character, also passes. To see the registration status, legal name and return filing, search the GSTIN on the GST portal.
How do I check a GSTIN on the GST portal?
Open services.gst.gov.in, choose Search Taxpayer → Search by GSTIN/UIN, enter the GSTIN and the captcha. The portal shows the legal and trade name, the status, the date of registration and the taxpayer type. No login is needed.
Can I find the PAN from a GSTIN?
Yes, for regular registrations: characters 3 to 12 are the PAN. The PAN’s 4th character tells you the type of holder — P for an individual, C for a company, F for a firm or LLP, and so on.
Why does my GSTIN fail the check?
Usually a typo: a letter O instead of a zero, I instead of 1, two characters swapped, or a missing or extra character. The tool shows which check character the first 14 characters call for and suggests a correction when a common slip explains the mismatch. If the GSTIN is printed that way on an invoice, ask the supplier to confirm it.
What does the 13th character mean?
How many registrations that PAN has in the same State: 1 for the first, then 2 to 9 and A to Z. A business with separate registrations for different verticals in one State has GSTINs that differ only in this character (and the check character).
Is a GSTIN the same as a GST number?
Yes. “GST number”, “GST registration number” and “GSTIN” all mean the same 15-character identifier.