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UDI system — overview & structure

Applies to

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.

Disclaimer

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 entityCarrier format
GS1GS1-128 barcode or GS1 DataMatrix 2D code; RFID
HIBCCHIBC barcode (Code 39, Code 128, DataMatrix)
ICCBBAISBT 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 classUDI on label required fromEUDAMED registration required from
MDR Class III, IVDR Class D26 May 202126 May 2021
MDR Class IIa, IIb, IVDR Class B, C26 May 202326 May 2023
MDR Class I, IVDR Class A26 May 202526 May 2025

Note: actual implementation timelines have been subject to legislative adjustments — always verify current requirements in the Official Journal.

UDI obligations — who does what?​

ActorObligation
ManufacturerAssign UDI; place UDI carrier on label; register Basic UDI-DI and device information in EUDAMED
ImporterVerify that device has UDI carrier; record UDI in their own systems
DistributorVerify UDI carrier is present; record UDI in distribution records
Healthcare institutionsKeep records of UDIs for implanted devices; store and manage implant cards

Official references​

ReferenceDescription
MDR Art. 27UDI system
IVDR Art. 24IVDR UDI system
MDR Annex VIUDI — information to be submitted
Commission Implementing Regulation (EU) 2017/2185List of issuing entities
IMDRF/UDI WG/N7FINAL:2013International UDI guidance