Global Trade Item Number (GTIN) – Item IdentityGlossary

Global Trade Item Number (GTIN) – Item Identity

Q: Is GTIN the same as UPC or EAN?

GTIN is the global framework. UPC and EAN are regional implementations. In GS1 Application Identifiers, GTIN is encoded as AI (01) regardless of regional naming.

Q: When do I need to assign a new GTIN?

Assign a new GTIN when a change materially affects the trade item (e.g., count/size, formulation impacting allergens or claims, brand/ownership). Govern under Change Control and update labels, catalogs, and EDI.

Q: How does GTIN interact with lot and serial numbers?

GTIN identifies the item, AI (10) identifies the batch, and AI (21) provides a unit-level serial. Many regulated items carry all three plus expiry (17) for end-to-end traceability.

Q: Do I need different GTINs for unit, inner, case, and pallet?

Yes. Assign distinct GTINs per packaging level and ensure labels and WMS rules reflect those levels. Use GTIN-14 at higher levels as appropriate.

Q: How do I handle catch-weight or variable-measure items?

Keep GTIN stable for identity and encode variable measure using appropriate AIs (e.g., net weight (310n)). Enforce scale integration and Catch Weighing controls to avoid mislabeling.

Q: What if a customer insists on their own item code?

Include both GTIN and the customer's code. Maintain cross-references in ERP and publish them via EDI catalogs to prevent picking errors and ASN disputes.

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

Updated October 2025 • GS1, Item Master Data, Serialization & Labeling • ERP, MES, WMS, QA/RA, Supply Chain

The Global Trade Item Number (GTIN) is the universal key for product identity. It uniquely identifies trade items—anything priced, ordered, or invoiced—across markets and packaging levels. Encoded with AI (01) in GS1 barcodes (GS1‑128, GS1 DataMatrix, GS1 QR), the GTIN is the backbone that connects item masters, labels, WMS locations, MES recipes, and customer documents. In regulated operations, GTIN forms the “what” that pairs with “which lot” (AI 10) and “which logistics unit” (SSCC) to deliver rapid, defensible traceability through EPCIS, EDI, and on‑pack scanning.

“If lot proves origin and SSCC moves logistics, GTIN is the single source of truth for what the item is—everywhere.”

TL;DR: Treat GTIN (AI 01) as controlled master data across ERP/MES/WMS and your label ecosystem. Allocate GTINs by packaging level, follow change rules for variants and content changes, validate barcodes with Label Verification/Barcode Validation, and bind GTIN to the executing record (eBMR, pick/pack, ASN/EPCIS). Combine GTIN with lot, expiry (AI 17), and optional serialization (AI 21) for end‑to‑end identity and recall readiness.

1) What GTIN Covers—and What It Does Not

Covers: global product identity for trade items at all packaging levels (unit, inner, case, pallet). GTIN variants (e.g., GTIN‑12/‑13/‑14) support regional and hierarchical use. In GS1 barcodes, AI (01) carries the 14‑digit GTIN (with leading zero/indicator as needed), allowing scanners to unambiguously resolve the item. GTIN underpins item master data, price lists, BOM/recipe references, pack‑and‑ship processes, and customer EDI catalogs.

Does not cover: batch or lot identity (AI 10), unique unit serials (AI 21), or logistics unit identity (AI 00). GTIN also does not replace regulatory identifiers like UDI; it complements them where UDI is required.

2) Legal, System, and Data Integrity Anchors

While GTIN is a commercial identifier, its governance intersects with GxP and consumer protection. Where electronic records reference GTIN, they must meet 21 CFR Part 11/Annex 11 expectations under CSV, with access control, electronic signatures, and immutable audit trails. Item identity changes must be controlled via Document Control and Change Control. In food and pharma, GTIN aligns with KDE/EPCIS requirements by providing a stable item key that pairs with lots, dates, and event data.

3) The Evidence Pack for GTIN Control

Create a reusable “GTIN dossier” that proves the assignment and correct downstream use of each GTIN:

Allocation rules: When a new GTIN is required (e.g., changes to declared net content, formulation that affects consumer perception, regulatory status, or brand/ownership).
Hierarchy mapping: Unit ↔ inner ↔ case ↔ pallet relationships (GTIN‑14 at higher levels), with indicator digits where applicable.
Label templates & parsing: Barcodes containing AI (01) tested for syntax, check digit, and coexistence with other AIs (10, 17, 21, 310n).
System interfaces: ERP/MES/WMS master data sync, EDI catalogs, customer cross‑references.
Verification records: Label Verification/Barcode Validation grades and rework dispositions.
Traceability hooks: Linkage to BMR/MBR/eBMR and warehouse pick/pack transactions.
Retention & governance: Approvals/effective dates under Record Retention.

Store evidence centrally so auditors can trace from a label to the governing master data and back again, without recalculation or manual lookups.

4) From Item Master to Shipping—A Standard Path

1) Item Master Creation. Define GTINs for each sellable/configured level, approve under Document Control, and synchronize to ERP/MES/WMS.
2) Execution. During weigh/dispense and pack, MES reads the GTIN from the active recipe/order; labels render AI (01) with the correct packaging‑level GTIN; scanners validate the barcode before goods move off the line.
3) Warehouse & ASN. WMS enforces GTIN on pick/pack and publishes the same identity in EDI ASNs and EPCIS events.
4) Customer Receipt. The customer’s system matches the received GTIN to their catalog, minimizing relabels and disputes.

If any prerequisite fails (wrong GTIN at pack, check digit error, template mismatch), block release until corrected. Fixing identity after shipment is slow and expensive.

5) Designing GTIN Allocation—A Practical Method

Use a simple, defendable approach to decide when a new GTIN is warranted:

Consumer‑relevant change: If a change materially alters what the consumer receives (size, formulation, allergens, regulated status, brand/owner), assign a new GTIN.
Packaging level clarity: Assign distinct GTINs at each hierarchy level; avoid reusing unit GTINs for cases or pallets.
Markets & languages: Where markets require different label content or legal declarations, consider separate GTINs to avoid mixed stock.
Private label & co‑pack: Maintain separate GTINs per brand owner; map to internal material codes inside ERP/MES.
Variable‑measure items: Keep identity (GTIN) stable while encoding measure in companion AIs (e.g., net weight (310n)); handle catch‑weight with Catch Weighing logic.

Document your policy and keep a decision log so future teams understand why a GTIN was introduced or retired.

6) Master Data—Cross‑References Without Confusion

GTIN is global; customers may still use proprietary catalog numbers. Maintain cross‑reference tables (customer item ↔ GTIN ↔ internal SKU) and publish them in EDI catalogs. Ensure MES and WMS always store and display the canonical GTIN with the item to prevent picking by obsolete identifiers.

7) Data Integrity—Proving Label = Master

For each printed barcode containing AI (01), persist the encoded string, parsed AIs, template version, and device IDs. Lock label artwork and data sources under Labeling Control. Keep approvals and effective dates in the audit trail. Avoid “smart” printers that compute GTINs on the fly; the source of truth must be validated master data, not device scripts.

8) Sampling, Verification & Cross‑Checks

Implement layered verification: (i) in‑line decode checks (is AI 01 present, correct length, valid check digit?); (ii) periodic print quality verification against your label SOP; (iii) cross‑checks against the item master (does the scanned GTIN match the order/recipe level?). Tie failures to Deviation/CAPA with documented rework.

9) Equipment Status—Printers, Scanners & Verifiers

Barcoding affects identity and traceability; treat it as GxP‑relevant where applicable. Keep printers, scanners, and verifiers in qualified state (IQ/OQ/PQ) with known calibration status. Capture device IDs with each verification. If a device drops out of status, block label print and shipment until remediated.

10) Labels, Claims & Supporting AIs

On consumer packs, GTIN shares space with claims, regulatory marks, and variable data. Ensure companion AIs are consistent: AI 10 (lot), TNE guardbanded net content when using (310n)/(315n), expiry (17), and optional serial (21). Where you claim volume but fill by mass, harmonize identity and claims via controlled density factors and artwork control.

11) Warehouse Status & Logistics Units

In WMS, GTIN governs pick rules, substitutions, and pack consistency. Cases and pallets add (00) SSCC to group trade items for shipping; keep the GTIN present on homogenous cases and ensure the item identity flows into EDI ASNs and EPCIS commissioning/aggregation events. Use dynamic lot allocation with GTIN to satisfy customer preferences without relabeling.

12) GTIN in Daily Control—Speed with Confidence

Embed GTIN gates in your processes: prevent weigh/dispense without a matching GTIN at the order level; block pack when the packaging‑level GTIN and template version are mismatched; require a valid decode before inventory moves out of Hold. Show operators the item description tied to the scanned GTIN to avoid near‑lookalike swaps (same artwork, different strength or size).

13) Metrics That Demonstrate Control

GTIN Decode Success at pack/receipt (first‑pass read %).
Check‑Digit Error Rate per 10k labels; trend by line/printer.
Template/GTIN Mismatch Incidents (blocked before ship).
Customer ASN Disputes involving identity (should trend to zero).
Cross‑reference Accuracy (customer item ↔ GTIN matches) at inbound QC.
Recall Drill Latency from GTIN+lot to shipped SSCCs and customers.

These KPIs connect barcode quality and master‑data governance to operational speed and customer satisfaction.

14) Common Pitfalls & How to Avoid Them

Reusing unit GTIN for cases. Assign separate GTINs per packaging level; enforce via label templates and WMS rules.
Printer‑side GTIN generation. Move all logic to validated systems; printers render, they don’t decide identity.
Customer code ≠ GTIN. Always include GTIN on labels and in ASNs, even when customers also require their own item numbers.
Uncontrolled changes. Seemingly small changes (count, size, allergens) may require a new GTIN—govern under Change Control.
Mixed cases with a single GTIN. Keep cases homogeneous or label/declare each component appropriately; avoid ambiguity.
Shadow spreadsheets. Centralize GTINs in ERP/MDM and integrate to MES/WMS; keep approvals and history under Document Control.

15) What Belongs in the GTIN Dossier

Allocation policy and decision log; hierarchy mapping (unit/inner/case/pallet) with effective dates; label templates and parse/verify evidence; ERP/MES/WMS integration specs; customer cross‑reference tables; audit trail of changes; retention schedule; and references to related SOPs (Labeling Control, Record Retention, Data Integrity). Link GTIN records to recipe management and products/formulas master data for full lifecycle control.

16) How This Fits with V5 by SG Systems Global

GTIN as Master Data. In the V5 platform, GTINs are versioned and effective‑dated with approvals in the audit trail. V5 maintains hierarchy links (unit/inner/case/pallet) and propagates them to MES orders and WMS pick/pack rules.

Execution & Interlocks. Label print jobs pull AI (01) from the active order; V5 blocks printing if the GTIN doesn’t match the packaging level or fails check‑digit/syntax checks. Device status is enforced via calibration status, and failed verifications open guided remediation workflows.

Traceability & Customer Alignment. V5 emits EPCIS events and builds EDI ASNs with the same GTINs you printed. Dashboards track decode success, template mismatches, cross‑reference accuracy, and recall drill latency from GTIN+lot to shipped SSCCs.

Bottom line: V5 operationalizes GTIN governance and use—from item master to label, warehouse, and customer documents—reducing relabels, ASN disputes, and recall time.

17) FAQ

Q1. Is GTIN the same as UPC or EAN?
GTIN is the global framework; UPC (common in North America) and EAN (common elsewhere) are GTIN implementations. In GS1 AIs, GTIN is encoded as AI (01) regardless of regional naming.

Q2. When do I need to assign a new GTIN?
When changes materially affect the trade item (e.g., count/size, formulation impacting allergens or claims, brand/ownership). Manage decisions under Change Control and update labels, catalogs, and EDI.

Q3. How does GTIN interact with lot and serial numbers?
GTIN identifies the item; AI 10 identifies the batch; AI 21 provides item‑level serials. Many regulated items carry all three plus expiry (17).

Q4. Do I need different GTINs for unit, inner, case, and pallet?
Yes—assign a distinct GTIN for each packaging level and ensure labels and WMS rules reflect those levels. Use GTIN‑14 at higher levels where appropriate.

Q5. How do I handle catch‑weight or variable‑measure items?
Keep GTIN stable for identity and encode the variable measure using appropriate AIs (e.g., net weight (310n)). Enforce scale integration and Catch Weighing controls to avoid mislabeling.

Q6. What if a customer insists on their own item code?
Include both: print and transmit GTIN and the customer’s code. Maintain cross‑references in ERP and publish them via EDI catalogs to prevent picking errors.