Supermarket point of sale in South Africa, and the grocery product data behind it

POS for a South African supermarket is a multi-lane supermarket point of sale system that scans every barcode, prices weighed goods by the kilogram and charges the right VAT on every line, and structured product data for grocery is the item master behind it: one record per product holding its barcode, unit of measure, price and VAT rate, stored once and read by every lane. In South Africa two of those fields decide whether the day reconciles. The VAT rate, because part of a grocery range is zero-rated and sits on the same shelf as taxed goods. And the unit of measure, because a weighed item has to price per kilogram and not per pack.

POS for a South African supermarket, and structured product data for grocery: the short answer

A supermarket point of sale system in South Africa has four jobs at every lane: read the supplier's barcode, read the price your own scale printed on a weighed pack, apply 15% or zero VAT to each line, and print a slip SARS accepts. Structured product data for grocery is what lets it do all four without a cashier guessing. Each item is described the same way, in fields a machine can use, rather than in a name someone typed at the counter.

The rest of this guide goes field by field: where the barcode comes from, how a weighed item gets its price, which foods are zero-rated, and what the till slip must show. If you want the store side first (lanes, scales, scanners and plans), our grocery and supermarket POS page covers it.

What a supermarket till has to do that a coffee-shop till does not

A restaurant till handles a steady stream of orders from one screen. A supermarket lane scans a full basket, weighs the tomatoes, reads a pack from the deli counter, and does it again at every other open lane at the same time. The load is not the number of sales. It is the number of line items, and it bunches up at the after-work rush and on month-end Saturdays.

That shapes what you should buy. A till that fetches each price over the internet will feel fine in a demo with one lane open and start stuttering when every lane is scanning. Many lanes reading one catalogue at once is a different engineering problem from one busy counter, which is why price lookups have to be local and instant: the product catalogue sits on a database in the store, not only in someone's cloud.

TimeWorks has supplied point of sale systems from Cape Town since 1999. The stores that struggle are rarely the ones with the oldest hardware. They are the ones whose product file was never built properly.

Structured product data is what makes the rest work

For grocery, these are the fields that earn their place in the item master. Fill them for every line before you worry about the till.

Get one field wrong and the error repeats on every sale of that item at every lane until someone finds it, usually at a stock count or a VAT reconciliation. A correction made once in the item master is correct everywhere, which is the whole point of structuring it.

Barcodes: GTINs from your suppliers, in-store numbers for what you weigh

A fixed-pack item carries a GTIN printed by the manufacturer, and the lane simply reads it. GTIN stands for Global Trade Item Number, the number under the barcode, and GS1 South Africa is licensed to create GTINs for Africa and is the only registered provider in the SADC countries. Your item master should store the GTIN exactly as printed, as the scan key, so one scan finds one record.

A weighed item has no manufacturer barcode, so your scale prints one. These are not GTINs. GS1's summary of prefixes 20 to 29 explains that 13-digit numbers starting 02 or 20 to 29 are Restricted Circulation Numbers for national, sector or in-store use, are not globally unique, and are not GTINs. The same document sets out the formats GS1 South Africa uses:

• Prefix 02: a four-digit item number you assign, a verifier digit, a five-digit price and a check digit.
• Prefixes 20 to 24: numbers the retailer assigns in full, for in-store use.
• Prefixes 28 and 29: a number assigned by GS1 South Africa and the manufacturer, a verifier digit and the price.

Two things follow for your product data. First, the South African formats that carry a value (02, 28 and 29) carry the price, never the weight, and GS1 South Africa recommends this variable measure solution for produce. So the lane must read the price out of the barcode, and your item master must hold the short in-store item number that the scale prints in front of it. Second, the verifier digit is, in the GS1 South Africa glossary's words, a digit calculated from the measure field and "used to check that the data has been correctly composed". Ask whether your POS checks it, because a mis-keyed label should be refused at the lane, not charged.

Loose produce that never touches a printing scale gets priced at the counter instead. TimeWorks supports CAS and Mettler-Toledo POS weighing scales with programmable PLU keys and tare memory, connected over RS-232 serial or USB, so the lane reads the weight and applies the per-kilogram price from the item master. A Zebra LI2208 handheld barcode scanner reads EAN-13, Code 128 and UPC-A. That gives you three routes to one price, and the item master has to know which route each item takes.

Price per unit and per kilogram: one number, three places

SARS's VAT 404 Guide for Vendors puts it first among its ten principles: all prices charged, advertised or quoted by a vendor must include VAT at the applicable rate. So the selling price in your item master is the VAT-inclusive shelf price, per unit for a pack and per kilogram for anything weighed.

That one number has to reach three places unchanged: the shelf label, the scale, and the lane. If the scale holds its own copy of the per-kilogram price, it drifts the first time someone changes a price in the back office and forgets the scale. The safer setup sends prices from the item master to the scale and prints shelf and pack labels from the same records, on thermal label printers that handle EAN-13 and Code 128. Then a price change is one edit, not three.

For a pack the scale printed, the lane does not multiply anything. It reads the price embedded in the barcode and checks the item number against the item master for the description, department and VAT rate. For loose items weighed at the lane, the POS multiplies the weight by the stored per-kilogram price. Both are only as right as the record behind them.

VAT: zero-rated and standard-rated on the same shelf

SARS levies VAT at the standard rate of 15%, and a limited range of goods is zero-rated. The VAT 404 guide lists the basic foodstuffs zero-rated under section 11(1)(j) and Part B of Schedule 2 of the VAT Act: brown bread, brown bread flour, samp, dried mealies and mealie rice, hens' eggs, fresh vegetables and fruit, dried beans, lentils, maize meal, rice, pilchards in tins or cans, vegetable cooking oil (but not olive oil), milk, cultured milk, milk powder and dairy powder blend, and edible legumes and pulses.

The exceptions are where grocery data goes wrong. The same guide says the zero rate does not apply when a zero-rated food is prepared for immediate consumption, such as a pre-packed salad with dressing bought at a supermarket, or when a standard-rated item is supplied with it, such as a pack of rice with a sachet of flavouring. SARS Binding General Ruling 38 covers vegetables and fruit: they stay zero-rated when cut, sliced or peeled, but only if they have not been cooked or treated other than to keep them in their natural state. So the same butternut is zero-rated raw and cut on the shelf, and standard-rated once your deli roasts it.

That is a product-data rule, not a till rule. Give the raw item and the prepared item separate records, each with its own VAT rate, and the lane gets it right every time. A zero-rated line captured as standard-rated overcharges the customer and overstates your output tax, and nobody notices until a reconciliation. The guide also says zero-rating must be supported by documentary proof acceptable to the Commissioner, so keep a note of why each item carries the rate it does.

Your till slip is a tax document

The slip your lane prints is a tax invoice, and which kind depends on the basket. The VAT 404 guide sets out the bands:

• R50 or less: no tax invoice is required, but a till slip showing the VAT charged is still needed to support the output tax you declare.
• Less than R5 000: an abridged tax invoice may be issued. It may leave out the customer's name, address and VAT number, and the quantity.
• R5 000 or more: a full tax invoice under section 20(4), carrying the customer's name, address and VAT registration number as well as your own, a serial number and date, a full and proper description, the quantity, and the price and VAT.

The guide adds that an abridged invoice may not be used for a zero-rated supply, and that a full tax invoice must be issued for zero-rated supplies even under R5 000. Ask your accountant how that applies to your trade customers.

That threshold catches supermarkets. A trade customer filling a bakkie crosses R5 000 easily, and if your lane cannot capture their VAT number at the counter they cannot claim the input tax. This is also where the description field earns its keep: "MILK" on a slip is not a full and proper description. Ask to see a full tax invoice printed on a real lane.

Keeping the lane trading when the link goes

Power is the part South African retailers have already solved, with inverters and generators. The connection still stops sales, and it drops for reasons that have nothing to do with the grid: a fibre cut, a failed router, an outage at the provider.

So ask one question of any till you are shown. With the internet down, can a lane still scan, price, take cash and print a compliant slip, and will those sales reconcile when the link returns? Have the salesperson pull the network cable mid-basket and finish the sale in front of you. A system with a local database carries on. We wrote up how that plays out during load shedding separately.

Cloud-only, hybrid and SQL-backed, on the things a supermarket cares about

The longer form of that argument is in our cloud versus SQL-backed comparison. For the terminals, printers and drawers themselves, see our retail POS hardware guide.

Customer data comes with obligations

The moment you run a loyalty programme you are processing personal information and the Protection of Personal Information Act 4 of 2013 applies. Section 19 requires you to secure the integrity and confidentiality of that information with appropriate, reasonable technical and organisational measures. Section 21 requires a written contract with any operator processing it for you, making sure they maintain those same safeguards. Your POS vendor, if they hold your customer records, is that operator.

Ask the vendor, in writing, where customer records are stored, who can read them, and how long they are kept after you cancel. Vendors differ on all three.

What to ask before you sign

• storefront
  Can I see a full basket scanned with every lane open, in a store like mine?
• wifi_off
  Pull the network cable mid-sale. Does the lane finish it and print a compliant slip?
• scale
  Does the lane read the price from a 02 or 2x scale barcode, check the verifier digit, and match the item number to my item master?
• percent
  Where is each item's VAT rate set, and who can change it?
• receipt_long
  Can the lane capture a customer's VAT number when a basket reaches R5 000?
• database
  Who owns the product catalogue if I leave, and in what format do I get it?
• support_agent
  What is the response time on a Friday at 17:00, and where is the technician based?

Common questions

Where to start

Export your product file before you speak to any vendor. Count the items with no barcode, no unit of measure or no VAT rate, and check that every weighed item has an in-store number your scale can print. That count tells you how much of your checkout problem is the till and how much is the catalogue, and it is usually the catalogue. Running a smaller format? The same fields apply to a convenience store till. New to the terms here? Our guide to what a point of sale system is covers the ground.