GTIN, SGTIN and LGTIN: Product Identity

Almost every passport programme makes this decision early, often without noticing it is a decision. Choosing an identity level determines what the passport can ever say, and changing it afterwards means re-identifying products that have already shipped.

What are the three levels?

The three are nested rather than alternative. An SGTIN contains the GTIN plus a serial; an LGTIN contains the GTIN plus a lot. A system holding serials can always answer type-level questions, and one holding only a GTIN cannot answer anything below it.

How do you choose?

By asking what varies between units, and whether anything the passport must record attaches to that variation. If two units of the same model are genuinely interchangeable and nothing will ever be recorded against one and not the other, type identity is sufficient.

1. Does composition or origin vary between production runs? If yes, at least batch level.
2. Will evidence attach to a consignment, as with timber under EUDR? Batch level.
3. Will service, repair or ownership be recorded per unit? Item level.
4. Does resale or authentication matter commercially? Item level.
5. Does the product change state in use, like a battery? Item level.

The last question is the decisive one for a surprising number of products. Anything whose condition changes and whose condition matters to a later owner needs item identity, because a type-level record cannot hold a history that differs between units.

What does each level cost?

Type identity is nearly free because it already exists on the barcode. Batch identity requires the production system to carry lot through to labelling, which most manufacturing already does internally and frequently loses at packing.

Item identity costs the most: unique marking per unit, a record per unit, and the storage and retrieval to support it. For a product made in millions the record count is large, though individually small, and modern systems handle it — the harder part is usually the marking process on the line.

Why the decision is hard to reverse

Identity is applied at manufacture and carried on the product. Deciding two years later that item identity is needed does nothing for units already made, because there is no way to retrofit a unique mark to products in the field.

That produces a split estate: newer units with serials and older units without, and every downstream process has to handle both indefinitely. Choosing the higher level initially and using only part of it is usually cheaper than the reverse.

What do the regulations require?

Regulation (EU) 2024/1781 does not fix a level in the framework; delegated acts specify it per product group. The signals so far point to different answers per category, which is the correct outcome given how differently products behave.

Regulation (EU) 2023/1542 effectively requires item-level identity for batteries, because state of health is per unit. EUDR evidence attaches to consignments, which is batch. Textiles are likely to sit at type or batch level for most products.

How does this appear in a data carrier?

A GS1 Digital Link URI encodes the key in its path, so the identity level is visible in the identifier itself. A carrier holding a serialised key resolves to a specific unit; one holding only a GTIN resolves to the model.

This has a practical consequence for printing. A type-level code can be printed identically on every package; a serialised code must be generated and applied per unit, which changes the printing equipment and the verification step on the line.

What about products already serialised for other reasons?

Many manufacturers already apply serial numbers for warranty, traceability or anti-counterfeiting, and assume the passport requirement is therefore satisfied. Usually it is not, because an internal serial is not the same thing as a standards-based identifier.

An internal serial is unique within your systems and meaningless outside them. An SGTIN is globally unique and resolvable by any party, which is what allows a recycler or a regulator with no relationship to you to retrieve the record. The existing serial is a useful input rather than a substitute.

The practical migration is to keep the internal serial as an attribute and issue a standards-based key alongside it, so existing systems keep working while the product gains an identity the outside world can use.

Can you mix levels?

Yes, and complex products usually should. A vehicle carries item identity while its steel carries batch identity and its fasteners carry type identity. The passport for the vehicle references the others at whatever level each supports.

That mixed model is normal rather than a compromise. Requiring item identity throughout a bill of materials would be enormously expensive and would add nothing for components that are genuinely interchangeable.