A GSTIN looks like random letters and numbers: 27ABCDE1234F2Z5. It is not random at all. Once you know the pattern, you can tell which state a business is registered in, whose PAN it belongs to, and whether a number on a bill even looks genuine, in about ten seconds.
The 15 characters, piece by piece
Take the example 27ABCDE1234F2Z5.
| Position | Example | Meaning |
|---|---|---|
| 1–2 | 27 | State code (27 = Maharashtra) |
| 3–12 | ABCDE1234F | PAN of the business |
| 13 | 2 | Registration number under that PAN in the state |
| 14 | Z | Default character |
| 15 | 5 | Check digit |
Characters 1 and 2: state code. Every state and union territory has a two-digit GST code. 27 is Maharashtra, 24 is Gujarat, 07 is Delhi, 29 is Karnataka, 33 is Tamil Nadu. A business registered in two states has two GSTINs that start differently. Our state pages list every state’s code.
Characters 3 to 12: PAN. The next ten characters are the business’s PAN. A proprietor’s GSTIN carries the owner’s personal PAN. A company’s carries the company PAN. This is how one PAN links all registrations of the same business across states.
Character 13: entity number. If the same PAN has more than one registration in the same state (for example, two business verticals), this counts them: 1 for the first, 2 for the second, and so on.
Character 14: Z. This is a default character, usually Z.
Character 15: check digit. Calculated from the other 14 characters. If someone mistypes a GSTIN, the check digit usually stops making sense, and the portal rejects it.
How to verify a GSTIN
Before you give credit to a new buyer, or before you pay a new supplier who charged you GST, check their number:
- Go to the official GST portal, gst.gov.in.
- Choose Search Taxpayer, then Search by GSTIN.
- Enter the 15 characters.
- Read the legal name, trade name and status.
Composition taxpayers cannot charge you GST. If a supplier’s GSTIN shows them as a composition taxpayer and their bill still shows CGST and SGST, something is wrong. You cannot claim that tax as credit. See our composition scheme guide.
Why the state code matters on every bill
The first two digits decide your tax type. If your GSTIN and your buyer’s GSTIN start with the same state code, and the goods are delivered in that state, the sale is intra-state: CGST + SGST. If the codes differ, it is usually inter-state: IGST. Our CGST, SGST and IGST guide has examples.
Billing software like Vyapar uses the buyer’s state on the party to make this choice. Save the GSTIN and state correctly once and every bill gets it right.
Spotting a fake or wrong GSTIN on a bill
- Fewer or more than 15 characters.
- PAN part that does not follow the PAN pattern (five letters, four digits, one letter).
- State code that does not match the address on the bill.
- Search Taxpayer shows “cancelled”, a different name, or nothing at all.
If a supplier’s GSTIN is wrong, their sale will not appear in your GSTR-2B, and you cannot claim the credit. See input tax credit basics.
Your own GSTIN in Vyapar
Enter your GSTIN once in your company details in Vyapar, and it prints on every invoice and feeds your GST reports. See our setup guide.
Decoding a sample GSTIN
Take a made-up example: 27ABCDE1234F1Z5.
| Characters | Value | Meaning |
|---|---|---|
| 1-2 | 27 | State code (27 is Maharashtra) |
| 3-12 | ABCDE1234F | PAN of the business |
| 13 | 1 | First registration under this PAN in the state |
| 14 | Z | Default letter |
| 15 | 5 | Check character |
So this is the first GST registration, in Maharashtra, of the business whose PAN is ABCDE1234F. If the same business registers in Gujarat, its GSTIN there starts with 24 but carries the same PAN in the middle.
Three quick checks before you save a party
- Length is 15 characters. Anything else is a typo.
- The state code matches the party’s address. A Delhi address with a GSTIN starting 27 needs a second look.
- Search it on the GST portal (Search Taxpayer > Search by GSTIN) and check the legal name and status are active.
These checks take a minute and protect your input credit, because a wrong GSTIN on a purchase bill means the credit never shows up for you. See input tax credit basics.
Frequently asked questions
How many characters are in a GSTIN?
Fifteen: a 2-digit state code, the 10-character PAN, an entity number, a default Z and a check digit.
What do the first two digits of a GSTIN mean?
They are the state code where the business is registered, for example 27 for Maharashtra and 07 for Delhi.
How can I check if a GSTIN is valid?
Use Search Taxpayer on gst.gov.in and enter the GSTIN. Check the name, status and taxpayer type.
Can one business have more than one GSTIN?
Yes. A business registered in several states has one GSTIN per state, and it can have more than one in the same state for separate verticals.
