Most traceability projects start with the same question: at what level should we identify the product? Is a batch number enough, does every unit need its own serial number, and where do the GS1 standards fit in? The wrong choice creates cost in both directions. Identification that is too coarse leaves counterfeiting and channel diversion invisible; identification that is too fine creates needless load on the production line, in the warehouse and in the information systems. This article covers the basic building blocks and which question each one answers.
Identifiers: by what they identify
GTIN: the product type
GS1's Global Trade Item Number (GTIN) identifies products that are priced, ordered or invoiced at any point in the supply chain. The important point is this: a GTIN identifies a product type, not a single box. The same GTIN is identical on every unit of that product in the market. Each packaging level — consumer unit, inner pack, case or pallet — can be identified with its own GTIN. It comes in four formats, GTIN-8, GTIN-12, GTIN-13 and GTIN-14, and is fully compliant with ISO/IEC 15459-4. A GTIN can be encoded in a barcode or an EPC/RFID tag; it is read at the checkout, at goods-in in the warehouse, or when a medicine is administered in a hospital. It is also used to identify products in electronic catalogues, order and invoice messages and on web pages.
Batch number: the production group
According to GS1, groups of products with similar production and usage characteristics can be distinguished with data elements added to the GTIN, such as a batch (lot) number and an expiry date. The batch level is designed to track a production batch as a whole: which raw material it was made from, on which line, on which date, and which customers it was shipped to.
Serial number: the individual unit
When a GTIN is used together with a serial number, each unit is identified uniquely. In pharmaceuticals, EU rules require that this serial number be at most 20 characters and that the probability of guessing it be negligible. Türkiye's Pharmaceutical Track and Trace System likewise carries the GTIN, serial number, batch number and expiry date together on every pack.
SSCC: the logistic unit
The 18-digit Serial Shipping Container Code (SSCC) identifies logistic units such as cases, pallets or packages that have been assembled for storage and transport. The number does not change throughout the logistic unit's life. Matched with despatch advice messages sent before shipment, it speeds up goods receipt and invoicing. GS1 treats the SSCC as a critical key in traceability because it uniquely identifies every logistic unit and its contents; the code is compliant with ISO/IEC 15459-1.
Data carriers: ways of putting information on a product
An identifier and the symbol that carries it are different things. The same data can be carried in a linear barcode, a two-dimensional code or an RFID tag.
GS1 DataMatrix
GS1 DataMatrix is a two-dimensional symbol that carries a lot of data in little space, can be printed directly on a product, and thanks to its error correction remains readable even when damaged or poorly printed. GS1's healthcare community notes that pharmaceutical traceability legislation in more than 75 countries, including Türkiye, is met with DataMatrix, and recommends that QR codes not be used for product identification on healthcare products.
QR codes and GS1 Digital Link
GS1 Digital Link is the method for encoding identifiers such as GTIN, GLN and SSCC, together with batch number, serial number and expiry date, in the form of a standard web address (URI). In retail the aim is for every product to carry a single multi-purpose two-dimensional code that can both be read at the checkout and lead to instructions for use, certificates or traceability information. The brand can update the digital content it points to without changing the code on the packaging. In healthcare applications, Digital Link is not embedded in the two-dimensional code; the data in the DataMatrix is converted to a Digital Link address by the mobile app where needed.
Print quality and human-readable data
However well a code is designed, it is useless if it cannot be read. The EU's pharmaceutical rules require the Data Matrix to be printed on a smooth, low-reflectance surface with a quality grade of at least 1.5 under ISO/IEC 15415, and the data to also appear in human-readable form where the packaging allows. Manufacturers are also obliged to verify the quality of the printed code. In sectors with no such obligation, these thresholds still make a good reference when setting quality control criteria on the production line.
Sunrise 2027
GS1's Sunrise 2027 initiative refers to retail's transition from linear barcodes to two-dimensional codes such as QR (GS1 Digital Link) and GS1 DataMatrix. GS1 US describes the date not as a legal requirement but as a readiness target, and recommends a phased transition.
Event data: EPCIS and linking units together
Identifiers answer the question "what is this". The question "where, when and in whose hands" needs event data. GS1's EPCIS standard defines interoperable data sharing about the status, location, movement and custody of products. One of the core pieces of information EPCIS supports is aggregation: placing individual products in cases, cases on pallets and pallets in containers. This means that when an SSCC is read, the individual units inside it can be reached, and a shipment can be managed without scanning each one. Version 2.0 of EPCIS also standardises the inclusion of sensor data and product and process certificates in event messages, which matters in processes such as cold chains where conditions must be recorded as well.
When each level is enough
The right level follows from the question you want to answer:
- GTIN alone: enough for checkout sales, stock and catalogue management. For products with low recall and counterfeiting risk and low unit value, it often does the job on its own.
- GTIN with batch number and expiry date: needed in food, cosmetics and chemicals for targeted recalls, shelf-life management and tying quality problems back to their source. But because thousands of products in the same batch carry the same code, a copied batch code cannot be told apart.
- GTIN with serial number: needed for high-value products, products carrying a health risk, and products requiring warranty or channel control. Each unit's history can be followed; the same number read in two places shows up as an anomaly.
- SSCC and event data: makes it possible to manage shipments in warehouse and distribution processes. Linked with serialised products, the information about which unit went to which dealer forms by itself.
- GS1 Digital Link: a suitable approach for brands that want to give consumers information, move to two-dimensional codes in retail, and prepare for regulations that foresee a QR-based data carrier, such as the EU Digital Product Passport.
Numbering and authentication are not the same thing
None of these identifiers proves on its own that a product is genuine. The GTIN is the same on every box, the batch number repeats across thousands of boxes, and even a serial number can be photographed from a genuine product's packaging and reproduced. Numbering answers "which product is this", not "is this product genuine". That is why it is meaningful that the EU's pharmaceutical rules ask for the unique identifier together with an anti-tampering device, and have the code decommissioned when the medicine is dispensed to the patient.
In practice a strong design uses three layers together:
- A standard identifier (GTIN, plus batch and serial number where needed)
- A physical element that is hard to copy
- A data layer that watches reads and flags codes seen repeatedly or in unexpected places
Spectrace's solutions correspond to these layers. Tagvex secure labels provide unique numbering at batch or unit level; by recording every change of hands from the production line to the warehouse, the dealer and the customer, they make a copied code visible as a repeated or unexpected read. Grafex provides the physical verification layer with an invisible signature embedded in the existing packaging design and printed on the existing line. Both solutions are verified with the mobile app on a smartphone.
Conclusion
Batch numbers, serial numbers and GS1 identifiers are not alternatives to each other but answers to different questions. The right design comes from combining these building blocks according to the product's risk profile, regulatory expectations and the data to be shared with business partners. One question helps when deciding: when a problem arises, what is the smallest unit whose answer I need to find?
Sources
- GS1, Global Trade Item Number (GTIN) Executive Summary, 2015
- GS1, Serial Shipping Container Code (SSCC) Executive Summary, 2015
- GS1, GS1 Digital Link, 2026
- GS1, 2D barcodes, 2026
- GS1, The key role of GS1 DataMatrix barcodes for product identification in healthcare, 2021
- GS1, EPCIS and CBV, 2026
- GS1 US, What is GS1 Sunrise 2027?, 2026
- EUR-Lex, Commission Delegated Regulation (EU) 2016/161 on safety features, 2016
- İEİS, Pharmaceutical Track and Trace System (Turkish), 2026
- European Commission, Digital Product Passport, 2026
