What is GS1?
GS1 is a global, neutral, not-for-profit organisation that maintains the standards for uniquely identifying products, locations, assets and logistic units, and for capturing and sharing those identifiers through barcodes, RFID and electronic messages. Well-known GS1 standards include the GTIN product number, the EAN-13 barcode on consumer goods, the SSCC for pallets and the 2D codes GS1 DataMatrix and GS1 QR Code. In OT environments, GS1 is the shared language that lets production, packaging lines, warehouses and the rest of the supply chain understand each other: a single scanned code returns the product number, batch number, expiry date and serial number in one go.
🧠 Where does GS1 come from and how is it organised?
GS1 grew out of two organisations. In the United States, the retail industry selected the Universal Product Code (UPC) in 1973, and the Uniform Code Council (UCC) was founded in 1974 to administer it. In 1977 the European Article Numbering Association (EAN) followed in Brussels, introducing the 13-digit EAN number. EAN and UCC signed a global cooperation agreement in 1990, and since 2005 they have operated worldwide under the name GS1.
The head office (GS1 Global Office) is in Brussels. Beneath it sit around 120 national member organisations, such as GS1 Netherlands, GS1 UK and GS1 US, which together serve more than two million user companies. A company joins the member organisation in its own country and receives a GS1 Company Prefix: a unique block of numbers from which it may issue its own GTINs, SSCCs and location numbers. This keeps the numbers globally unique without a central database having to assign every individual code.
🔧 Which identification keys and data carriers does GS1 define?
GS1 draws a strict line between the key (the number that identifies something) and the data carrier (the barcode or tag that holds that number). The same GTIN can therefore be encoded in an EAN-13, a GS1-128 or a DataMatrix.
| GS1 key | Full name | Identifies | Typical format |
|---|---|---|---|
| GTIN | Global Trade Item Number | A product or packaging level | 8, 12, 13 or 14 digits |
| SSCC | Serial Shipping Container Code | A logistic unit (pallet, case) | 18 digits |
| GLN | Global Location Number | A company, site or dock door | 13 digits |
| GRAI | Global Returnable Asset Identifier | A returnable item (crate, container) | 14 digits plus optional serial |
| GIAI | Global Individual Asset Identifier | An individual asset (machine, tool) | up to 30 characters |
GTIN, SSCC and GLN end in a check digit calculated with the modulo-10 algorithm (in a GRAI it sits in the fixed numeric part, before the optional serial), so a scanner or PLC can reject a misread number immediately.
The main data carriers are:
- EAN-13 / UPC-A - a 1D code holding only the GTIN, designed for the retail checkout
- ITF-14 - a robust 1D code for outer cases, often printed directly onto corrugated board
- GS1-128 - a 1D code based on Code 128 that carries multiple data fields; the standard for pallet labels with an SSCC
- GS1 DataBar - a compact 1D code for fresh produce and small items
- GS1 DataMatrix and GS1 QR Code - 2D codes that hold a lot of data on a small surface and remain readable when partly damaged
- EPC/RFID - UHF radio transponders that can be read in bulk without line of sight
🔢 How do Application Identifiers work?
What sets GS1-128, GS1 DataBar Expanded, GS1 DataMatrix and GS1 QR Code apart from an ordinary barcode are the Application Identifiers (AIs): short numeric prefixes in brackets that say which data element follows. This lets a single symbol carry several fields that every system interprets in the same way.
| AI | Meaning | Format |
|---|---|---|
| (00) | SSCC | 18 digits |
| (01) | GTIN | 14 digits |
| (10) | Batch or lot number | up to 20 characters |
| (11) | Production date | YYMMDD |
| (15) | Best before date | YYMMDD |
| (17) | Use by / expiry date | YYMMDD |
| (21) | Serial number | up to 20 characters |
| (414) | GLN of a physical location | 13 digits |
| (8004) | GIAI (individual asset) | up to 30 characters |
An example of the human-readable text below a pharmaceutical code is (01)08712345678906(17)271231(10)AB123(21)X7Y8Z9. Inside the symbol, a special start character
(FNC1) signals that the content is GS1 data. Variable-length fields such as batch and serial number are
terminated with a separator character (GS, ASCII 29) whenever another field follows. This is exactly where
things often go wrong in practice: a scanner that does not pass on the separator, or software that parses
the string as fixed-length, produces a wrong batch number.
🏭 How is GS1 used in OT environments?
On the factory floor, GS1 bridges the physical flow of goods and the data in MES, ERP and WMS. Typical applications:
| Use case | Example |
|---|---|
| Operator panel input (HMI) | An operator scans the GS1 code on a raw-material bag; the MES retrieves batch and expiry date and checks that the right material is being dosed |
| Automatic weighing and labelling | SCADA or the line control generates a GS1-128 pallet label from order data and recipe data in the MES |
| Track & trace | Pallets and units are followed through production and logistics using SSCC codes (Tracking and Tracing) |
| Linkage to the Historian | The batch number from AI (10) is linked to process conditions, so that after a complaint the temperature and pressure curves of that batch can be retrieved immediately |
| Aggregation | A Vision camera reads all serial numbers in a case and links them to the pallet’s SSCC (parent-child relationship) |
| Asset management | Tools, moulds and spare parts receive a GIAI so that assets can be registered unambiguously |
For integration with the control layer, the OPC UA companion specification OPC 30010 (AutoID Devices), developed with AIM, describes barcode scanners, RFID readers and OCR cameras as OPC UA objects with methods such as Scan. This allows a scanner to be integrated into the line independently of its vendor. In an ISA-95 architecture, interpreting AIs belongs at level 3 (MES), while the PLC mainly handles the read trigger and the good/reject decision.
⚖️ Which regulations make GS1 coding mandatory?
GS1 itself is not a law, but several European and US rules require unique identification, and GS1 standards are a common way to meet them:
- Falsified medicines - Delegated Regulation (EU) 2016/161 has applied since 9 February 2019. Prescription medicines, apart from a few exempted products, carry a unique identifier with product code, serial number, batch number and expiry date in a 2D Data Matrix code, with a print quality of at least 1.5 under ISO/IEC 15415 as a presumption of conformity.
- Medical devices - the EU MDR (2017/745) and IVDR (2017/746) require a UDI. Implementing Decision (EU) 2019/939 designated four issuing entities: GS1, HIBCC, ICCBBA and IFA. The US FDA also uses UDI.
- Digital Product Passport - under the ESPR (EU) 2024/1781 and the Batteries Regulation, products receive a data carrier that points to the Digital Product Passport. GS1 Digital Link, also published as ISO/IEC 18975 since 2024, turns a GTIN into such a web address.
In regulated manufacturing, such as pharmaceuticals under GAMP and 21 CFR Part 11, scan and print data fall under data integrity: a misprinted serial number is a quality deviation, not a cosmetic issue.
🛠️ How do you introduce GS1 coding on a production line?
- Arrange membership - request a company prefix from your national GS1 organisation and assign a GTIN to each packaging level (unit, case, pallet).
- Choose the carrier per level - EAN-13 or GS1 DataMatrix on the product, ITF-14 or GS1-128 on the outer case, GS1-128 with SSCC on the pallet label.
- Define the AIs - decide which fields are mandatory (for example 01, 10, 17, 21) and where they come from: ERP, MES or the line itself.
- Verify print quality - use a verifier according to ISO/IEC 15416 (1D) or 15415 (2D) and an inline camera that reads every code and rejects faulty ones.
- Integrate the scanners - connect scanners via OPC UA or a fieldbus rather than keyboard emulation, validate check digits and separators, and log every read and print action.
- Secure the chain - serialisation servers and printers are part of the OT network; place them in their own segment and treat scanned data as untrusted input that is validated before it reaches a database.
The voluntary GS1 initiative Sunrise 2027 asks retailers to make their checkout scanners capable of reading 2D codes by the end of 2027. Manufacturers designing packaging today should therefore plan for a GS1 DataMatrix or a QR code with GS1 Digital Link alongside, or instead of, the EAN-13.
❓ Frequently asked questions
What is the difference between GS1 and EAN?
EAN was the original name of the European organisation that introduced the 13-digit article number in 1977. Since 2005 that organisation has operated worldwide as GS1. The term EAN lives on in the name of the EAN-13 barcode, which is a GS1 data carrier for the GTIN.
How much does a GS1 barcode cost?
GS1 codes are not sold individually: a company joins its national GS1 organisation and pays an annual fee, usually based on turnover or the quantity of numbers needed. Within its assigned GS1 Company Prefix, the company then issues its own GTINs and SSCCs. Barcodes bought from resellers are not linked to the company and are rejected by many retailers.
Is a GS1 DataMatrix the same as an ordinary DataMatrix?
A GS1 DataMatrix is an ordinary DataMatrix (ECC 200) that starts with the FNC1 character and encodes its data using GS1 Application Identifiers. This allows a scanner to recognise that the content follows the GS1 structure. A DataMatrix without FNC1 can contain any text and does not follow GS1 rules.
What is GS1 Digital Link?
GS1 Digital Link is a GS1 standard that turns a GTIN and other GS1 keys into a web address, for example with /01/ followed by the GTIN in the path. A QR code holding such an address works at checkouts that can read 2D codes and opens product information on a smartphone. Since 2024 the syntax has also been published as ISO/IEC 18975.
Why is GS1 relevant to OT security?
GS1 codes are external input that flows straight into MES, ERP and sometimes PLC logic. Scanners that act as a keyboard can enter any character sequence, so scanned GS1 data must be validated for AI structure, length and check digit. Printers and serialisation servers on the packaging line also belong in a separate network segment.
Does RFID use GS1 standards too?
Yes, GS1 maintains the EPC standards for RFID, which store a serialised GTIN, an SSCC or a GIAI in a UHF tag. With EPCIS, GS1 also defines how events such as production, shipping and receiving are shared between companies. This creates traceability that goes beyond scanning a single code.
📌 In summary
GS1 is the global organisation behind the identification keys (GTIN, SSCC, GLN, GIAI) and data carriers (EAN-13, GS1-128, GS1 DataMatrix, GS1 QR Code, EPC/RFID) that make products, batches, locations and assets uniquely identifiable. In OT environments, GS1 connects the packaging line to MES, ERP and the historian, and it underpins mandatory serialisation in pharmaceuticals, medical devices and the Digital Product Passport.