Three identifiers sit at the heart of the DPP model and are easy to confuse. The unique product identifier ties the carrier to the passport; the EU ESPR also references a unique operator identifier (the economic operator) and, where relevant, a unique facility identifier. The UPI is the one printed on or embedded in the product, and it must stay stable for the product's life so the passport remains resolvable years after sale.
In practice the ecosystem expresses the UPI using existing GS1 keys — most often a GTIN, optionally with a serial number for item-level passports — carried in a GS1 Digital Link URL. The exact required identifier scheme for each product group is set in that group's delegated act, so check the relevant act rather than assuming one format fits all.
Frequently asked
Is a unique product identifier the same as a GTIN?
Not exactly. A GTIN is one common way to express the UPI, but the UPI is the regulatory concept (the ID that resolves to a passport and registers it in the EU DPP Registry). For item-level passports a GTIN is usually combined with a serial number.
Where is the unique product identifier stored?
It is encoded in the product's data carrier — typically a GS1 Digital Link QR, NFC or RFID tag — and recorded centrally in the EU DPP Registry, which maps each identifier to the URL of its passport.
Can two products share one unique product identifier?
It depends on the granularity the delegated act requires: a model/GTIN-level identifier can cover all items of one product, while item-level or batch-level passports need a serialised identifier so each unit or batch resolves to its own passport.