Why Identification Is the Foundation of Every DPP

A passport without a reliable, persistent, globally unique identifier is not a passport — it's a document. The EU's ESPR regulation is explicit that the DPP must be linked to the physical product through a data carrier, and that link must remain functional for the product's entire commercial life. When a product changes hands ten times across five countries over fifteen years, the identifier must still resolve to current, accurate data.

This is not a trivial requirement. Internal part numbers are unique within a company but collide across companies. SKUs are unique within a retail system but mean nothing to a recycler. Trade names change. Companies merge and rename product lines. The identification system for a DPP needs to be grounded in a global, registry-backed standard that survives all of these changes. That is exactly what GS1 identifiers provide.

Understanding how identification works also clarifies the scope of the implementation work when you set up your DPP system. The identification architecture is a decision that affects labelling, packaging design, database structure, ERP configuration, and supplier data requirements simultaneously. It needs to be made early.

The Three Levels of DPP Identification

The ESPR regulation and the delegated acts being developed for specific product categories define three levels at which a DPP can operate. Understanding the distinction between them is essential before choosing an identification strategy.

Model Level

At the model level, all physical units of a given product design share one DPP. Every washing machine of model X from manufacturer Y has the same GTIN, and that GTIN points to one passport that describes the product as designed: its material composition, its energy class, its repairability score, its manufacturer details, its certifications.

The model-level DPP is the baseline. Even product categories that will eventually require batch or item-level identification will still have model-level data — the item-level DPP inherits model-level attributes and adds unit-specific ones. For products where the regulation only requires model-level identification (likely to include most textile categories), the model GTIN is all you need as the identifier.

GTINs at the model level use GS1's Global Trade Item Number standard. GTINs come in 8-, 12-, 13-, and 14-digit variants (EAN, UPC, ITF-14). For most consumer products, the GTIN-13 (the barcode you see on retail packaging) is the relevant identifier. Manufacturers obtain GTINs by becoming a GS1 member in their country — the GS1 member organisation assigns a company prefix, and the manufacturer constructs GTINs using that prefix plus product codes they assign themselves.

Batch Level

Batch-level identification adds a layer of specificity. Products from the same production run share a batch or lot number. The batch DPP inherits the model DPP and adds batch-specific attributes: production date and location, batch-specific quality test results, the specific material suppliers used for that production run (which may differ from the nominal BOM if a substitute was approved).

Batch identification matters for traceability. If a quality issue is discovered, the batch number lets you identify exactly which products are affected and where they are in the supply chain. For regulated products where material composition can vary between production runs — food contact materials, medical devices, products with variable recycled content — batch-level identification provides the granularity regulators need.

In GS1 terms, a batch is expressed as an Application Identifier (AI 10) in a GS1 barcode or RFID tag. In a GS1 Digital Link URI, the batch is appended as a query parameter: https://id.gs1.org/01/09506000134376/10/ABC12345 where /01/ introduces the GTIN and /10/ introduces the batch number.

Item Level: Serialised Identification

Item-level identification means every physical unit has its own unique identifier and its own DPP record. This is the most demanding level to implement but provides the richest data. A serialised product's DPP can include: the specific unit's assembly date, the results of any end-of-line tests performed on that unit, the repair history accumulated over the product's life, and (for high-value products) provenance documentation establishing the chain of custody from manufacture to current owner.

The EU Battery Regulation — one of the first ESPR-adjacent instruments to specify DPP requirements in detail — requires item-level DPPs for industrial batteries and EV batteries. Each battery will need a unique serial number, and the DPP associated with that serial number will need to store state-of-health data, charging history, and eventually the battery's decommissioning record.

In GS1 terms, a serial number is Application Identifier AI 21. The GS1 Digital Link for a serialised item looks like: https://id.gs1.org/01/09506000134376/21/SN-00012345. The combination of GTIN and serial number is globally unique.

GS1 Digital Link: The Standard That Makes It Work

Knowing that a product has a GTIN and a serial number is not enough. The DPP requirement adds something those identifiers have never historically needed to do: resolve to a live, updatable web resource. That is exactly what GS1 Digital Link defines.

GS1 Digital Link is a URI syntax standard that embeds GS1 identifiers in a web address. The URI structure is: https://{resolver-domain}/{primary-key-AI}/{primary-key-value}[/{qualifier-AI}/{qualifier-value}]. The domain can be the manufacturer's own domain or GS1's resolver service. The path encodes the identifier using AI codes. Optional qualifiers add batch or serial context.

When this URI is encoded into a QR code and scanned, the resolver at the target domain interprets the path and redirects the scanner to the appropriate DPP record. If the scanner is a consumer smartphone, it gets a product information page. If it's a regulatory system, it requests machine-readable JSON. If it's a recycling facility scanner, it receives disassembly instructions. The same QR code serves all audiences through content negotiation — responding differently based on the Accept header in the HTTP request.

This is a critical architectural point. The physical label on a product printed in 2025 might still need to serve accurate data in 2040. With GS1 Digital Link, the QR code does not contain data — it contains an address. The data it resolves to can be updated without touching the label. The identifier on the label is permanent; the DPP content it points to evolves with the product.

Data Carrier Formats

GS1 Digital Link URIs can be encoded in several physical carrier formats. Each has different characteristics that make it suitable for different product and use-case contexts.

QR Codes

QR codes are the expected primary carrier for most DPP implementations because they are readable by any smartphone without special hardware. For consumer-facing products, this is the obvious choice. The QR code needs to be sized and printed at sufficient resolution for reliable scanning — GS1 publishes minimum size guidelines based on the data density of the encoded URI. For industrial products where the label may be exposed to heat, solvents, or abrasion, durable QR code printing technologies (laser etching, chemical etching on metal, ceramic printing) should be specified.

RFID and NFC

RFID (particularly UHF Gen 2 per ISO 18000-63) and NFC tags can carry GS1 identifiers and are used where QR codes are impractical: high-speed logistics lines where line-of-sight scanning is impossible, products with irregular surfaces, or products where the label area is too small for a readable QR code. NFC is particularly relevant for high-value consumer products (luxury goods, electronics) where the tap-to-verify experience has user experience advantages. The Electronic Product Code (EPC) standard from GS1 defines how GTINs and serial numbers are encoded in RFID tags.

Data Matrix and GS1-128

For industrial and regulated products already using GS1-128 barcodes or Data Matrix codes (common in healthcare and logistics), these can carry GS1 Digital Link syntax and continue serving their existing purposes while also supporting DPP resolution. This is a useful migration path for manufacturers who don't want to change their labelling lines — the same carrier format, extended to carry the Digital Link URI in addition to the existing barcode data.

Assigning Identifiers: Practical Steps

If your organisation is already a GS1 member and uses GTINs for retail barcodes, your company prefix is already assigned. The practical work is: confirm that all products requiring DPPs have GTINs assigned, create GTINs for any products that are currently identified only by internal codes, and establish the serial number and batch number format conventions for categories requiring those levels.

Serial number format matters more than it might seem. Some ERP systems assign serial numbers with leading zeros that get stripped. Some use formats that contain characters (slashes, spaces) that require URL encoding in a Digital Link URI and can cause scanning errors. Defining serial number formats that are URI-safe and consistent across all systems — ERP, manufacturing execution system, DPP platform — before implementation begins prevents significant rework.

The DPP requirements checklist includes a section on identifier readiness that walks through the specific questions your team should answer before starting DPP implementation. The introduction to digital product passports provides broader context on what the identifier system serves within the overall DPP framework.

Common Mistakes in DPP Identifier Implementation

The most common mistake is treating the DPP identifier as an IT problem and delegating it entirely to the development team. It is a business decision with regulatory consequences. The choice of identification level (model vs. batch vs. item) determines how data is collected, stored, and maintained for every product in scope. That choice should be made by someone who understands both the regulation and the operational implications.

The second common mistake is building identifier systems that are not globally unique. Internal serial numbers that are unique within a factory but not globally are insufficient. If you manufacture in three countries and number serial numbers independently at each site, you can have collisions. The DPP platform will treat them as the same product. The fix — prefixing serial numbers with a site code, or using UUIDs — is trivial technically but requires coordinating changes across multiple manufacturing operations.

The third mistake is treating the QR code as a label design decision rather than a technical specification. The size, print resolution, substrate, and durability specification of the QR code are determined by the scanning environment, not by what looks good on the packaging. Involve your packaging engineering team in the carrier specification process before artwork is finalised.

Platform Support for Identification

The DPP-Tool platform supports all three identification levels natively. When creating a DPP, you specify whether it is model-level (GTIN only), batch-level (GTIN plus batch number), or item-level (GTIN plus serial number). The platform generates the GS1 Digital Link URI automatically and provides QR code generation with GS1-compliant sizing parameters. For high-volume serialised products, the batch API allows generating hundreds of serialised DPPs from a single template in one call.

The resolver infrastructure ensures that QR codes generated today will continue resolving correctly even as the underlying DPP data is updated. For manufacturers who need to host the resolver on their own domain (for brand consistency or data sovereignty reasons), a white-label resolver option is available on the enterprise plan — details on the pricing page.

Getting the identification architecture right is the prerequisite for everything else: the data model, the API integration, the compliance reporting. The step-by-step DPP creation guide takes identification as its starting point and builds the full implementation plan from there.