Every RFID tag carries a unique identifier, but without a common language to interpret that data, the information is only useful within a single organisation. This is exactly the problem that GS1’s Electronic Product Code (EPC) standards were designed to solve. By providing a universal framework for encoding product, asset, and item-level data on RFID tags, GS1 standards enable true supply chain interoperability across borders, industries, and technology platforms.
At the core of the GS1 EPC framework sits the EPC Tag Data Standard (TDS), which defines how identifiers are structured and encoded into the memory of UHF RAIN RFID tags. Rather than allowing every company to invent its own numbering scheme, GS1 assigns each organisation a unique Company Prefix that forms the foundation of every EPC. This prefix, combined with item reference numbers and serial numbers, creates globally unique identifiers that no two organisations can duplicate.
Understanding SGTIN, GRAI, and GIAI
The three most widely deployed EPC schemes each serve a distinct purpose. The Serialised Global Trade Item Number (SGTIN) extends the familiar GTIN barcode by adding a unique serial number to every individual item. Where a barcode identifies a product type, an SGTIN identifies the specific unit on the shelf. An SGTIN-96 encoding, for instance, packs the GS1 Company Prefix, item reference, and serial number into just 96 bits of tag memory, while SGTIN-198 supports alphanumeric serial numbers for industries that require them.
The Global Returnable Asset Identifier (GRAI) targets reusable transport items such as pallets, roll cages, kegs, and crates. These assets circulate between multiple trading partners and frequently cross organisational boundaries. Encoding a GRAI on a RAIN RFID tag allows each partner in the loop to read the same standardised identifier without needing proprietary software or lookup tables. This dramatically reduces asset loss and speeds up reconciliation at receiving docks.
The Global Individual Asset Identifier (GIAI) covers fixed and portable assets that belong to a single organisation, from laptop computers and medical devices to vehicles and test equipment. Unlike the GRAI, a GIAI does not require a separate serial component because the entire identifier is unique by definition. Encoding GIAIs on RFID tags turns manual asset registers into automated, real-time tracking systems.
How Standardised Encoding Enables Interoperability
The real power of these schemes becomes apparent when goods and assets move between companies. A manufacturer encoding SGTINs on tagged garments in Bangladesh can have those same tags read by a distribution centre in Rotterdam and again by a retailer in London, all without any prior data exchange agreement. The EPC binary structure includes a header that tells any compliant reader which scheme is in use, what the partition values are, and how to decode the Company Prefix. Software at each point in the chain can translate the binary into a GS1 URI and query shared databases through the EPCIS (Electronic Product Code Information Services) network.
This interoperability eliminates the costly middleware and custom integrations that plagued early RFID deployments. Before GS1 standards gained traction, each retailer or logistics provider often mandated its own tag format, forcing suppliers to maintain multiple encoding profiles. The EPC framework replaced that fragmentation with a single encoding standard that works across all GS1-compliant systems worldwide.
Practical Encoding in the Real World
Encoding an EPC tag in practice involves a few key steps. First, the organisation obtains a GS1 Company Prefix. Next, the appropriate scheme is selected based on the use case: SGTIN for trade items, GRAI for returnable assets, or GIAI for individual assets. The identifier fields are then assembled according to the TDS partition table, which determines how many bits are allocated to the Company Prefix versus the item or asset reference. Finally, the resulting binary string is written to the EPC memory bank of a UHF RAIN RFID tag using a compliant encoder or printer. Tools like the GS1 EPC Encoder/Decoder make it straightforward to verify that encoded values match expected URIs before tags enter the supply chain.
As industries from retail and healthcare to logistics and manufacturing continue to adopt item-level RFID, GS1 EPC standards remain the essential foundation. They ensure that every tagged item speaks the same data language, turning billions of individual RFID reads into a connected, interoperable global supply chain.