GSTIN — Goods and Services Tax Identification Number
A GSTIN is the 15-character alphanumeric ID issued to every GST-registered business in India. It encodes the state you're registered in, the PAN of the entity, an entity count, a fixed character, and a checksum. It must appear on every tax invoice you issue.
What each character means
- Characters 1–2 · State code. 27 = Maharashtra, 07 = Delhi, 29 = Karnataka, 33 = Tamil Nadu, and so on.
- Characters 3–12 · PAN. The 10-character PAN of the registered entity.
- Character 13 · Entity count. Number of registrations under the same PAN in that state. First one is 1, second is 2, up to 9 and then A–Z.
- Character 14 · Fixed 'Z'. Reserved character, always Z.
- Character 15 · Checksum. A single alphanumeric check digit computed from the previous 14 characters.
Where GSTIN must appear
Every tax invoice, credit note, debit note, and delivery challan you issue must show your GSTIN. In a restaurant or hotel context, this means:
- Every printed bill and every reprint.
- Every PDF invoice emailed or WhatsApp-shared to a guest.
- Every GST return you file (GSTR-1, GSTR-3B, GSTR-4).
- Your storefront display and, in many states, the menu itself.
How to verify a GSTIN
Public verification is available at the official GST portal. A quick sanity check: the state code should match the physical location of the business, and the PAN section should match the entity's PAN. The checksum can be validated computationally — most billing software does this automatically when a customer enters their GSTIN for a corporate bill.
In TBN software
Pass, Folio and Slate all print your GSTIN on every bill and every reprint. Pass keeps a separate GSTIN per outlet, so a business running several outlets under different registrations stays correct on each. Slate stores it once at property level and carries it onto invoices and PDF copies.