Barcodes, GS1 and traceability in the warehouse

Every time a scanner beeps in the warehouse, something important happens: a product, a parcel or a pallet is uniquely identified without a human needing to type a number. That's the whole idea of the barcode — and the reason why the global standards organization GS1 administers a shared numbering system that almost all retail and logistics industries are based on. If you understand GS1's three levels, you understand the data flow at any modern warehouse.

§Goods: GTIN and EAN-13

The cornerstone is GTIN — Global Trade Item Number — the item's unique product number. On consumer units it is most often printed as the familiar EAN-13 barcode with 13 digits: a GS1 prefix, the company's number, a serial number for the item and finally a check digit which the scanner uses to catch reading errors. The GTIN does not say anything about price or warehouse location — it is a key that your warehouse management system looks up to find all the item's data. The same physical item has one GTIN per trade unit: the piece, the tray and the box each have their own.

§Packaging: GS1-128 and application identifiers

At pallet and colli level, one number is rarely enough — you also want batch number, expiration date, and quantity. Here, the GS1-128 barcode is used, which can contain multiple data fields in one code. Each field is introduced by an application identifier (AI), a small code in parentheses that tells what the next digits mean. The most important ones are worth knowing by heart:

§The pallet: SSCC — logistics' number plate

SSCC stands for Serial Shipping Container Code and is an 18-digit serial number that identifies one specific shipment unit – typically a pallet. Where the GTIN says 'what is it', the SSCC says 'which specific pallet is it'. The SSCC is printed on the GS1 pallet label and makes it possible to report an entire pallet's contents electronically in advance (e.g. via an electronic delivery note), so receipt can get by with one scan instead of counting colli. It is the backbone of efficient goods receipt between fixed trading partners.

§FEFO and date management

Batch and expiry date are not just for recalls — they also control the picking order. The FEFO principle (First Expired, First Out) means that the item with the shortest remaining shelf-life is picked first, and this requires that the date is recorded per location or batch in the system. Without date control you end up with FIFO at best and with discarded goods at worst. Scanning on receipt is therefore not bureaucracy — it is where traceability is born.

§Next step: 2D codes

The industry is moving towards two-dimensional codes like QR and DataMatrix that can hold much more data in less space — GS1 works globally on the transition to 2D codes in retail under the name Sunrise 2027. For the warehouse this ultimately means that one code on the product can carry both GTIN, batch and date where today two codes are often needed. Scanners in modern warehouses already read both so the transition is mostly about labels and system setup.

• 01GTIN identifies the product type — EAN-13 is its most well-known barcode form
• 02GS1-128 carries multiple data fields via application identifiers
• 03SSCC (18 digits, AI 00) identifies the specific pallet or shipment
• 04Batch number (AI 10) and expiry date (AI 17) are the foundation for traceability and FEFO
• 052D codes are on the way and collect more data in one code

“Strong wind”

— The basic idea of the GS1 system