What is a unique product identifier (UPI)?

A unique product identifier (UPI) is the reference number that ties a physical product to its Digital Product Passport. Scan the code on the product, and the identifier tells the system exactly which passport to open.

The Ecodesign for Sustainable Products Regulation (ESPR) defines it in Article 2(30) as "a unique string of characters for the identification of a product that also enables a web link to the digital product passport". In other words, it is both an ID and a way to reach the data online.

How a unique product identifier works

1. The identifier is issued under an identification scheme, such as GS1, that guarantees no two products share the same string.
2. It is encoded in a data carrier, usually a QR code, placed on the product, its packaging or accompanying documents.
3. It resolves to the passport. When scanned, the identifier becomes a web link. A common way to do this is the GS1 Digital Link format, which puts the identifier inside a web address.
4. It is registered. The economic operator uploads the identifier to the EU DPP registry before the product is placed on the market.

ESPR Article 10(1)(a) says the identifier must be persistent. It cannot change during the passport's lifetime, so a code printed today must still work years from now.

Model, batch or item level

ESPR leaves the level of detail to each product group's delegated act (Article 9(2)(d)):

• Model level: one identifier for all units of the same model. A GTIN works well here.
• Batch level: one identifier per production batch, for example a GTIN plus a batch or lot number.
• Item level: one identifier per individual unit, for example a GTIN plus a serial number.

Item level gives the most detail but means printing a different code on every unit. The battery passport under the Battery Regulation is set per individual battery.

Other identifiers in the passport

The UPI is one of several identifiers ESPR uses. Annex III also lists:

• The GTIN, under ISO/IEC 15459-6 or equivalent, for products or their parts.
• Unique operator identifiers for the manufacturer and other actors in the value chain (Article 2(31)).
• Unique facility identifiers for the sites involved in making the product.
• Commodity codes, such as the TARIC code, and the importer's EORI number.

Article 12 sets the rules for operator and facility identifiers, and Article 13 sets up the registry that stores them alongside the UPI.

Standards to use

Annex III requires the data carrier, the UPI and the operator and facility identifiers to comply with ISO/IEC 15459 parts 1 to 6, or equivalent European or international standards, until harmonized standards are published. CEN-CENELEC's DPP standards series covers unique identifiers among its topics. GS1 identifiers comply with ISO/IEC 15459, which is why many brands start from the GTIN they already use.

How to prepare

• Decide your level per product group, based on the delegated act or, until it is adopted, on what you need for traceability and service.
• Reuse existing identifiers where you can. If your products already carry GTINs, adding batch or serial numbers is usually simpler than starting a new scheme.
• Make serial numbers unique and permanent, and never reuse them.
• Plan your print process for item-level codes, which need a variable QR code on every unit.
• Keep a register of every identifier you issue, ready to upload to the EU registry.