What is a weighing scale barcode?

Delis, butchers and grocers sell many items by weight. Rather than weigh again at the till, staff weigh the item at the counter scale, which prints a label with a barcode. When the cashier scans that label, the POS reads both which product it is and how much it weighs (or what it costs), and adds the line in one step.

These labels usually use EAN-13 with a special prefix, usually starting with 2, which tells the POS this is not a normal product barcode. The digits after the prefix are split into fields: a few digits of item code, then a few digits of weight or price, then a check digit. The exact layout depends on how the scale is programmed, so the POS has to be told how many digits are the item code and how many are the quantity.

The alternative is a scale connected directly to the till. The cashier puts the item on the scale at the counter and the POS reads the weight live. Direct scales suit produce at a single checkout; printed labels suit a deli counter where one person weighs and another rings up. Many grocers use both.

In SeroPOS, weighing at the till is done the second way: the SeroPOS app reads a scale connected directly (USB, serial or network) for products with Enable Weight, and falls back to a keypad that asks for the weight. The label format is a web back office setting only. Business Settings, then POS, has weighing scale barcode settings for the label prefix, product SKU length (1 to 9 digits) and quantity integer and decimal lengths, but scanning scale-printed labels is not a feature of the SeroPOS app, so plan your counter around a connected scale or typed weights.