UDI-DI Grouping for EUDAMED
The Unique Device Identifier, Device Identifier (UDI-DI), is the registration anchor in EUDAMED. Getting the grouping logic right determines whether your registration is accepted, rejected, or flagged for inconsistency during post-market surveillance.
UDI-DI, UDI-PI, and Basic UDI-DI
The UDI system under MDR Article 27 and IVDR Article 24 has three distinct levels. Understanding which level each piece of information belongs to is the prerequisite for correct EUDAMED registration.
The Basic UDI-DI is the primary identifier at which the device is registered in EUDAMED. It groups all device versions that share the same intended purpose, risk class, essential design, and manufacturing processes. One EUDAMED registration = one Basic UDI-DI.
The UDI-DI identifies a specific device version: a particular combination of model, configuration, size, or packaging. Multiple UDI-DIs (e.g. different sizes of the same device) can link to the same Basic UDI-DI. The UDI-DI is what appears on the device label.
The UDI-PI captures production-level information: lot number, serial number, manufacturing date, and expiry date. It changes with every batch. UDI-PI is never registered in EUDAMED; it lives only on the label and in the manufacturer's production records.
When do devices share a UDI-DI?
Devices share one UDI-DI when they are the same device version: same intended purpose, same model reference, same materials, same configuration, across different production batches. Only production-level variation (lot, serial, date) is captured in UDI-PI.
When must you issue a new UDI-DI?
MDR Annex VI Part C and the MDCG guidance on UDI define the specific change types that require a new UDI-DI. These are the most important ones.
Change in intended purpose
Any modification to the clinical indication, patient population, or body part targeted requires a new UDI-DI.
Change in device name or model reference
If the device is marketed under a new trade name or model number that a reasonable person would consider a different device, a new UDI-DI is required.
Material change with clinical impact
Changes to materials that affect safety, performance, or biocompatibility require a new UDI-DI. Cosmetic material changes that have no clinical impact do not.
Change in sterile/non-sterile status
Adding or removing sterilisation changes the product configuration at a level that requires a new UDI-DI.
Change in single-use vs reusable classification
A device previously classified as reusable that becomes single-use (or vice versa) requires a new UDI-DI.
New CE certificate or NB opinion
If a notified body issues a new or substantially revised certificate for a device, a new UDI-DI is typically required to reflect the new conformity status.
Basic UDI-DI in EUDAMED: what actually gets registered
EUDAMED registers at the Basic UDI-DI level, not the individual UDI-DI level. This means the device record, clinical data links, post-market surveillance references, and vigilance reports all attach to the Basic UDI-DI. The individual UDI-DIs (sizes, packaging) link to it.
The Basic UDI-DI must be assigned by an accredited UDI issuing entity (GS1, HIBCC, or ICCBBA). For manufacturers who are not yet members of a UDI issuing entity, obtaining the Basic UDI-DI assignment is a prerequisite step before EUDAMED registration can begin.
Common UDI-DI grouping mistakes
These errors account for the majority of EUDAMED data quality issues flagged during conformity assessment.
Creating a new UDI-DI for every batch
UDI-DI identifies the device version, not the production batch. Batch and lot information belongs in the UDI-PI (Production Identifier). Creating a new UDI-DI for each production run inflates the EUDAMED registry and complicates post-market surveillance.
Using the same UDI-DI after a design change
Manufacturers sometimes reuse an existing UDI-DI after modifying a device to avoid re-registration effort. This is a compliance violation. If the change meets any new-UDI trigger, a new UDI-DI must be issued and a new EUDAMED registration created.
Confusing UDI-DI with the Basic UDI-DI
The Basic UDI-DI is the registration unit in EUDAMED; it groups all UDI-DIs that share the same intended purpose and essential design. Not every UDI-DI change requires a new Basic UDI-DI. Confusing the two results in either under-grouped or over-fragmented registrations.
Not linking package-level UDI-DIs to the item level
Each packaging configuration (single, 5-pack, 50-pack) has its own UDI-DI, but all must be linked to the same Basic UDI-DI and ultimately to the same EUDAMED registration. Missing package-level links creates orphaned entries.
Applying the same UDI-DI to devices with different EMDN codes
If two configurations of a device have different primary intended purposes, and therefore different EMDN codes, they cannot share a UDI-DI. The EMDN code is device-version-specific and must be consistent with the UDI-DI it is registered against.
How EUDAMate structures UDI-DI grouping
When you upload your device data to EUDAMate, the platform automatically analyses your device list and groups entries by intended purpose, model, and configuration to identify which devices share a Basic UDI-DI and which require separate ones. Each grouping decision is documented in your Registration Decision Record.
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