The GST invoice checklist for small businesses

Why the details matter

A GST invoice is more than a bill. Your customer uses it to claim input tax credit, and you use it to report your sales. A missing or wrong field can delay a customer's credit and create awkward back-and-forth.

This checklist covers the fields commonly required on a tax invoice. Rules and thresholds change, so confirm current requirements with your chartered accountant or the GST portal.

The checklist

1. Your name, address and GSTIN.
2. A unique invoice number, in a consecutive series, and the invoice date.
3. The customer's name, address and GSTIN, if they are registered.
4. A clear description of each item or service.
5. HSN code for goods or SAC code for services, where applicable to your turnover.
6. Quantity and unit, and the taxable value after any discount.
7. The tax rate and amount, split into CGST and SGST for sales within a state, or IGST for sales across states.
8. Place of supply, which decides whether CGST and SGST or IGST applies.
9. Whether tax is payable on reverse charge, if relevant.
10. The total invoice value, and a signature or digital signature.

Mistakes to avoid

• Reusing or skipping invoice numbers, which makes your series hard to reconcile.
• Choosing CGST/SGST when the sale is inter-state, or the reverse.
• Leaving out the customer's GSTIN, which stops them claiming credit.
• Using the wrong HSN or SAC code, which can change the tax rate.
• Editing an issued invoice instead of issuing a credit or debit note.

Make it automatic

The less you type, the fewer mistakes you make. Keeping a price master with HSN codes and tax rates, and saving customers with their GSTIN, lets an invoice fill itself in. AOZO Accounting is built around exactly that: items with HSN, SKU and unit, customers with GSTIN, and GST invoices and quotations from the same place.