UDI system — overview & structure
Both MDR 2017/745 and IVDR 2017/746. UDI requirements are set out primarily in MDR Art. 27 / IVDR Art. 24 and MDR Annex VI / IVDR Annex VI.
This site provides general information only and does not constitute legal or regulatory advice. Always consult the official regulation text and a qualified regulatory professional.
What is the UDI system?
The Unique Device Identification (UDI) system is the EU's standardised framework for identifying medical devices throughout their commercial life — from manufacture to disposal. It enables:
- Traceability: linking specific manufactured units to the patients who used them
- Vigilance and recall: rapidly identifying affected devices and their distribution when safety issues arise
- Market surveillance: competent authorities can identify non-compliant devices
- EUDAMED integration: UDI data underpins the device registration module of EUDAMED
The EU UDI system is aligned with international frameworks (FDA UDI, IMDRF UDI guidance) to facilitate global harmonisation.
UDI structure — two components
Every device UDI consists of two parts:
UDI-DI — Device Identifier
The UDI-DI is the static component that identifies the device model or version. It is specific to:
- A particular manufacturer
- A specific device trade name and model
- A specific labelling version (if labelling changes, the UDI-DI changes)
- A specific packaging configuration (e.g. individual unit vs. 10-pack have different UDI-DIs)
The UDI-DI is assigned by the manufacturer in consultation with an accredited issuing entity (GS1, HIBCC, or ICCBBA). Each issuing entity has its own identifier format.
The Basic UDI-DI is a specific form of UDI-DI that is the primary key for a device in EUDAMED — it identifies the device at a model/version level across all unit configurations.
UDI-PI — Production Identifier
The UDI-PI is the dynamic component that identifies the specific production unit. It may include:
- Lot or batch number
- Serial number
- Manufacturing date
- Expiry date
- Software version (for software devices)
Not all UDI-PI elements are required for all devices — the applicable elements depend on device type, class, and what is required to ensure traceability.
How the UDI appears on the device — carriers
The UDI is communicated on the device label through a UDI carrier — a machine-readable representation of the UDI combined with the human-readable interpretation (HRI). The format depends on the issuing entity:
| Issuing entity | Carrier format |
|---|---|
| GS1 | GS1-128 barcode or GS1 DataMatrix 2D code; RFID |
| HIBCC | HIBC barcode (Code 39, Code 128, DataMatrix) |
| ICCBBA | ISBT 128 (primarily for blood and tissue products) |
The Human Readable Interpretation (HRI) must appear on the label adjacent to the carrier, in a format the user can read if the scanner is unavailable.
UDI application timeline — by device class
UDI requirements apply progressively across device classes:
| Device class | UDI on label required from | EUDAMED registration required from |
|---|---|---|
| MDR Class III, IVDR Class D | 26 May 2021 | 26 May 2021 |
| MDR Class IIa, IIb, IVDR Class B, C | 26 May 2023 | 26 May 2023 |
| MDR Class I, IVDR Class A | 26 May 2025 | 26 May 2025 |
Note: UDI implementation timelines have undergone legislative adjustments, and enforcement has been subject to grace periods. Always verify current requirements in the Official Journal and EUDAMED guidance, as timelines may differ from those listed above.
UDI obligations — who does what?
| Actor | Obligation |
|---|---|
| Manufacturer | Assign UDI; place UDI carrier on label; register Basic UDI-DI and device information in EUDAMED |
| Importer | Verify that device has UDI carrier; record UDI in their own systems |
| Distributor | Verify UDI carrier is present; record UDI in distribution records |
| Healthcare institutions | Keep records of UDIs for implanted devices; store and manage implant cards |
Related pages
- UDI-DI and UDI-PI explained
- EUDAMED UDI registration
- UDI labelling requirements
- UDI issuing entities
Official references
| Reference | Description |
|---|---|
| MDR Art. 27 | UDI system |
| IVDR Art. 24 | IVDR UDI system |
| MDR Annex VI | UDI — information to be submitted |
| Commission Implementing Regulation (EU) 2017/2185 | List of issuing entities |
| IMDRF/UDI WG/N7FINAL:2013 | International UDI guidance |
Complete the reference: 'MDR Annex VI — UDI system structure and requirements'