GS1 / GTIN – Global Identification for Trade Items, Cases, and Logistics Units

This topic is part of the SG Systems Global regulatory & operations glossary.

Updated October 2025 • Identification & Traceability • WMS, MES, QMS

GS1 is the global organization that maintains a common language of identification and barcoding for commerce and healthcare. Its most recognized identifier is the GTIN (Global Trade Item Number), the unique numeric key that identifies a trade item—anything priced, ordered, invoiced, or subject to regulatory distribution—from a single retail unit to a wholesale case or shipper. GTINs come in structured lengths (e.g., 12, 13, or 14 digits) and, together with other GS1 identifiers—GLN for locations, SSCC for logistics units, and application identifiers (AIs) for variable data like lot, serial, and expiry—form the backbone of label content and scan-based processes. In regulated manufacturing, GS1 standards drive unambiguous identification at goods receipt, warehousing, production, labeling, distribution, and recall, enabling genealogy, FIFO/FEFO, and release decisions that are traceable and automation-friendly.

“If two trading partners can’t agree on ‘what this is’ and ‘which exact unit it is,’ every downstream control—from directed picking to recall—rests on guesswork.”

At the core of the system is the GTIN, composed from a GS1 Company Prefix, an item reference, and a check digit. The representation of the GTIN depends on the packaging level and barcode symbology: retail point-of-sale often uses EAN-13/UPC-A; distribution layers use GS1-128 or ITF-14; healthcare and high-density industrial labels frequently use GS1 DataMatrix or QR to carry the GTIN alongside AIs like (10) for lot, (21) for serial, and (17) for expiry. GS1 extends beyond products: the GLN (Global Location Number) identifies legal entities, facilities, and functional locations; the SSCC (Serial Shipping Container Code) uniquely identifies pallets and cases; identifiers like GRAI and GIAI tag assets and instruments. Application identifiers provide a standardized dictionary for variable data, so when a scanner reads “(01)GTIN (10)Lot (17)Expiry (21)Serial,” systems can parse and validate content consistently under Barcode Validation rules.

1) What GS1 Covers and Why It Matters

GS1 standards define both identifiers and data carriers. Identifiers include the GTIN for products at any packaging level, GLN for parties and locations, SSCC for logistics units, and specialized keys for assets and relationships. Data carriers include linear barcodes (UPC/EAN, ITF-14, GS1-128) and 2D symbols (GS1 DataMatrix, GS1 QR). The data model is driven by application identifiers that annotate fields (e.g., “(01)” means the following 14 digits are a GTIN). In practice, the choice of carrier is dictated by density and environment: GS1-128 on cases for readability at distance; ITF-14 for corrugate; DataMatrix for small medical device labels; QR for consumer engagement while still remaining parseable by enterprise scanners. In regulated industries, GTIN and AIs enable machine-checkable identity and attributes (lot, expiry, serial) at Goods Receipt, during eBMR execution, and at Finished Goods Release, providing the link from each unit back to specifications under Document Control and forward into distribution for recall effectiveness.

2) GTIN Structure, Levels, and Versions

A GTIN is not just a “barcode number”—it is a structured key that can represent different packaging hierarchies. A consumer unit, an inner pack, and a case each can have their own GTINs that relate in a packaging hierarchy. GTIN-12 (UPC-A) is common in North America; GTIN-13 (EAN-13) internationally; GTIN-14 for trade units and cases. When items change in a way that affects trading partners (e.g., net content, dimensions, formulation affecting labeling), GTIN allocation rules require creating a new GTIN. Internally, controlled masters should map item revisions and label versions to the correct GTIN so scanner checks can prevent version drift. The GTIN identifies “what” the item is; AIs encode “which” specific lot or serial, and “until when” it is usable—fields that drive FEFO and Dynamic Lot Allocation within WMS/MES workflows.

3) From Label to System: Parsing AIs and Preventing Errors

Application identifiers standardize variable data so systems can parse labels consistently. Common examples include (01) GTIN, (10) Lot, (17) Expiry (YYMMDD), (21) Serial, (00) SSCC, (414) GLN of the physical location, and (422) country of origin. Operationally, this means Barcode Validation can enforce that the scanned GTIN matches the expected item in the order or eBMR step; the lot and expiry are captured into inventory; and a serial is recorded to enable unit-level traceability where required (e.g., medical devices or high-risk components). Blocks can be implemented to prevent picking if the scanned GTIN or lot does not match reservation, or to reject label application if the template’s encoded GTIN/AI set does not align to the approved label master. These controls reduce wrong-item, wrong-lot, and out-of-date errors, and they feed genealogy with clean, machine-read data rather than free text.

4) SSCC, GLN, and Hierarchical Traceability

Where the GTIN uniquely identifies the trade item, the SSCC uniquely identifies a logistics unit—a pallet, case, or tote—making it possible to track movements and contents through the supply chain. At receipt, scanning the SSCC can pull an ASN manifest, explode to child cases with their GTIN/lots, and post inventory rapidly with fewer handling errors. GLNs identify the ship-from, ship-to, and internal storage locations, improving auditability and supporting event capture for the EPCIS Traceability Standard. Together, GTIN + AIs + SSCC + GLN enable hierarchical, event-based traceability that makes recall simulation and release verification faster and defensible, with fewer reconciliation steps across WMS, MES, and ERP.

5) Symbology Choice and Print Quality

Selecting the right symbology and maintaining print quality are non-negotiable. Linear codes (UPC/EAN, ITF-14, GS1-128) remain best for rapid conveyor scanning and distance reads; 2D (DataMatrix/GS1 QR) is ideal for dense data on small labels or where both machine and human interactions occur. Print-and-verify loops should measure contrast, modulation, and quiet zones; verification grades can be used as a quality gate. Label templates and variable data should be managed under Document Control, and every print/apply event should be captured with scan-back in MES/WMS to prove what was printed is what was applied—an essential input to QA release and later complaint investigations.

6) Regulatory Interfaces and Master Data

While GS1 is industry-standard rather than law, many regulations reference or align to it in practice. Device UDI systems align with GTIN as the device identifier and AIs for production identifiers (lot, serial, expiry), and distribution/traceability obligations frequently assume GTIN-based identity. Effective use of GS1 demands disciplined master data: a single source of truth for GTIN allocation, packaging hierarchies, and associated label masters; mapping from GTIN to internal item codes; and governance to ensure that changes to formulation, net content, or labeling trigger GTIN changes where applicable. Master data should be versioned, auditable, and distributed to WMS/MES/labeling under CSV controls to maintain alignment and prevent silent drift across systems.

7) How This Fits with V5

V5 by SG Systems Global treats GS1 as the lingua franca across WMS, MES, and QMS. In WMS, Barcode Validation parses AIs to capture GTIN, lot, expiry, and serial at Goods Receipt, applies status and Bin / Location rules, and directs picking using GTIN reservations under FIFO/FEFO and Dynamic Lot Allocation. In MES, eBMR steps expect a specific GTIN family and packaging level; mismatches, expired dates, or wrong serials trigger exceptions or NCs. Labeling binds approved templates to GTINs under Document Control, and print/apply is closed-loop with scan-back. For outbound logistics, V5 generates SSCCs and (00) labels, records load events, and optionally publishes EPCIS events so customers can consume the same GTIN/SSCC/GLN semantics. All of this is captured with audit trails and aligns to ALCOA+ and Part 11 expectations for electronic records and signatures.

8) FAQ

Q1. Do we need different GTINs for each packaging level?
Yes. A retail unit, inner pack, and case should have distinct GTINs and be represented correctly in packaging hierarchies so systems can reserve, pick, and track at the right level.

Q2. When should a GTIN change?
Follow GTIN allocation rules: changes that affect trading partners—such as net content, dimensions affecting logistics, or formulation that drives labeling—typically require a new GTIN. Internal spec tweaks that do not change the commercial item may not.

Q3. GS1-128 vs GS1 DataMatrix—how do we choose?
Use GS1-128 for cases and pallets where long-distance linear scanning is needed; use DataMatrix for small labels or where dense data (GTIN + lot + expiry + serial) must fit in limited space.

Q4. Can we scan manufacturer GTINs directly, or must we relabel?
Prefer direct use if the labels meet your data requirements and approved symbologies/AIs. Relabel when supplier labels are incomplete, inaccurate, or not scannable in your environment.

Q5. How do GTIN and SSCC work together for traceability?
GTIN identifies what the item is; SSCC uniquely identifies the logistics unit carrying instances of that item. Scanning both links the physical handling unit to its contents and to events (ship, receive, store) for end-to-end traceability.

Related Reading
• Identification & Labels: Barcode Validation | EPCIS Traceability Standard
• Warehouse Execution: Goods Receipt | Directed Picking | Dynamic Lot Allocation | Bin / Location Management
• Records & Release: eBMR | Finished Goods Release | Batch Genealogy
• Governance & Integrity: Document Control | Data Integrity | 21 CFR Part 11