GST billing for supermarkets: what your POS should do

A supermarket counter has two jobs that pull against each other. It has to be fast, because a queue of customers is watching. And it has to be exact, because every bill becomes part of your GST return and your stock position. A good point of sale (POS) system does both without asking the cashier to think about tax.

Here is what that looks like in practice.

Tax on every line, not on the bill

A typical basket mixes items taxed at different GST rates, and some that are exempt. Calculating tax on the bill total is not good enough. Your POS should:

• Work out tax per line, using the rate set on each product.
• Show the CGST and SGST split on the invoice for sales within your state.
• Print the HSN code for each item. How many digits you need depends on your turnover, so confirm the rule with your accountant and make sure the software can store the full code.
• Let each product be priced tax-inclusive or tax-exclusive. Most retail shelf prices include tax, while some wholesale lines are quoted before tax. The system should handle both without manual arithmetic at the counter.

A summary your accountant can file from

At the end of the month, your accountant needs sales broken down by tax rate. If the POS gives you only a total, someone ends up rebuilding the numbers in a spreadsheet. Ask for a rate-wise summary that matches the invoices line for line, including returns.

Speed at the counter

GST accuracy is wasted if the counter is slow. Watch a cashier use the system during the demo:

• Can they scan, total, tender and print using only the keyboard and scanner, without reaching for the mouse?
• Are weighing-scale labels for loose items like vegetables, grains and sweets read automatically, with the weight and price taken from the barcode?
• Can they print an A4 tax invoice for a business customer and a 58 mm or 80 mm thermal receipt for everyone else?

A new cashier should be comfortable within an afternoon. If training takes a week, the queue will tell you.

Prices the till cannot change

Discounts typed in at the counter are one of the commonest ways margins disappear. The safest design is one where the server decides every price, tax and stock check, and an individual till simply cannot invent a discount. Promotions are set centrally and applied the same way on every counter.

Stock that moves with every bill

Tax and stock are two views of the same transaction. When an item is billed, purchased or adjusted, stock should change immediately, and the system should record a ledger line you can trace back to the bill or purchase that caused it. That ledger is what lets you answer "where did these 40 units go?" without guesswork.

Two features matter more as you grow:

• Reorder levels that produce a genuinely short list of what is running low, instead of a long report nobody reads.
• Branch transfers that are recorded at both ends, so stock in a van between stores is never simply missing.

Cash you can reconcile

Every shift should open with a float and close with a count. The system should record the difference per cashier and per shift, so a shortage is noticed the same day and not at the month end.

Reports that answer real questions

Beyond the GST summary, the reports you will actually use are simple: what sold, what is not moving, what it cost you, and what you made on it. If a report needs exporting and pivoting before it answers a question, it is not doing its job.

A short checklist for your next demo

1. Bill a mixed basket with at least three tax rates and one weighed item.
2. Check the CGST/SGST split and HSN codes on the printed invoice.
3. Process a return and see it appear in the rate-wise summary.
4. Try to change a price at the till.
5. Close a shift and look at the drawer report.

SuperMart POS is our billing system for Indian retail and was designed around exactly these checks. If you would like to try it with your own product list, get in touch.