The GST invoice checklist every Indian business should bill against

Most GST disputes we see at the customer end are not arguments about tax policy. They are arguments about a missing field. A buyer refuses to process a bill because the HSN code is absent, or the place of supply is wrong, or the invoice number restarted mid-year. The tax was right; the document was not.

What a compliant tax invoice must carry

Under the GST rules, a tax invoice is expected to carry a specific set of particulars. Treat these as mandatory fields in whatever system you bill from:

• Supplier name, address and GSTIN.
• A consecutive invoice number, unique within the financial year.
• Date of issue.
• Recipient name, address and GSTIN where the buyer is registered.
• Place of supply, and the state code — this is what decides CGST/SGST versus IGST.
• HSN code for goods or SAC for services, at the digit depth your turnover requires.
• Description, quantity, unit and taxable value per line.
• Rate and amount of tax, split into CGST, SGST/UTGST, IGST and cess as applicable.
• Whether tax is payable on reverse charge.
• Signature or digital signature of the supplier or an authorised person.

The place-of-supply trap

The single most common error is applying CGST and SGST to an interstate supply, or IGST to an intrastate one. The determining factor is the place of supply relative to your own state of registration — not the buyer's billing address, and not where the goods were picked up.

This is exactly the kind of rule that should never be a human decision at the counter. BillMantra reads the buyer's GSTIN, derives the state, compares it to your registered state and applies the correct split automatically. The cashier does not choose the tax head; the system does.

Invoice numbering across the financial year

Your invoice series must be consecutive and unique within a financial year. Many businesses either run one series forever, or reset it in January instead of April. Both create reconciliation problems at filing time.

A clean series looks like 25-26/INV/0001 — financial year, document type, sequence. It sorts correctly, reads unambiguously, and survives an audit.

Auto-reset on 1 April with the right prefix removes the whole class of problem. So does locking the series against manual edits once a document is issued.

Getting the credit note right

Returns and adjustments must reference the original invoice. A credit note that floats free of its parent document will update your customer's balance while leaving your stock and your GST liability inconsistent. Tie the note to the invoice, and let both the party ledger and the stock position move together in one atomic step.

Where to go next

If you want the detail behind each of these fields — including e-invoicing thresholds and e-way bill triggers — the BillMantra feature pages walk through the workflows screen by screen.