GST invoice format for shops: what to include on every tax invoice

Tax invoice vs simple receipt

Most walk-in sales at a shop only need a short receipt: items, prices and a total. A GST tax invoice is a fuller document, and it matters when your customer is a business that wants to claim input tax credit, or when you are required to issue one under GST rules. Many shops give a quick thermal receipt by default and print a full invoice only when asked.

This guide describes the common structure. Tax law has thresholds, exceptions and periodic changes, so please confirm what applies to your business, such as the number of HSN digits for your turnover or whether you are a composition dealer, with your chartered accountant.

The usual contents of a GST tax invoice

• The words "Tax Invoice" and your invoice number. Numbers should be unique and run in sequence for the financial year.
• The invoice date.
• Your shop's legal or trade name, address and GSTIN.
• The customer's name and address, and their GSTIN if the sale is to a registered business.
• A description of each item or service, with its HSN or SAC code, quantity and unit.
• The taxable value of each line after discount.
• The tax rate and the tax amount, split as CGST and SGST for sales within your state, or IGST for sales to another state.
• Place of supply, which decides whether the tax is CGST plus SGST or IGST.
• The total invoice value, often with the amount in words.
• A signature or authorised signatory line.

CGST, SGST and IGST in one minute

When you sell to a customer in the same state, the GST rate is split equally between the central tax (CGST) and the state tax (SGST). An 18% item, for example, carries 9% CGST and 9% SGST. When you sell to a customer in a different state, a single IGST at the full rate applies. Place of supply tells you which case you are in, so it must be correct on the invoice.

Mixed-rate baskets

Shops regularly sell goods at different rates on the same bill: for instance 5%, 12% and 18% items together. The clean way to handle this is to compute tax line by line and then summarise by rate. Doing it by hand with a calculator is where most counter mistakes happen, which is why storing the GST percentage on each product is worth the one-time setup.

Producing the invoice without double entry

In RathTech Billing POS you enter the sale once. It calculates tax per line using the GST percentage stored on each product, then prints either a short thermal receipt or a full A4 GST tax invoice with HSN codes, the CGST, SGST or IGST split, place of supply and the amount in words. Both come from the same saved bill, and you can reprint either from Sales History. The GST report totals the tax you collected over a period for your accountant.

The app does not file returns for you or generate e-invoices or e-way bills. It gives you organised, accurate invoices and reports to hand to whoever files them.

Common mistakes to avoid

• Skipping or repeating invoice numbers.
• Using the wrong place of supply, which produces the wrong tax split.
• Forgetting the customer's GSTIN on a business sale.
• Applying one rate to a mixed basket instead of tax per line.
• Editing a bill after issue instead of recording a proper return or credit note.

A practical routine for a small shop

For printer choices see 58mm vs 80mm thermal printers, and for how the rest of the counter fits together, read about offline billing.

1. Set up your shop details, GSTIN and receipt header and footer once.
2. Store the correct GST percentage and HSN code on each product when you add it.
3. Default to a thermal receipt for walk-ins and print the A4 invoice for business customers.
4. Check the GST report at month end and share it with your accountant.