Glossary Updates12 new terms added to the glossaries · October 2, 2026, 22:44 CEST
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Glossary · EU medical devices: MDR

Unique Device Identification (UDI)

Also known as: UDI, UDI system, UDI-DI, UDI-PI, Basic UDI-DI

Under the EU Medical Device Regulation (EU) 2017/745 (Article 27) and IVD Regulation (EU) 2017/746 (Article 24), Unique Device Identification (UDI) is the system that identifies devices through a code made of a device identifier (UDI-DI) and a production identifier (UDI-PI). The UDI is assigned using the standards of an issuing entity designated by the Commission and is carried on the label in machine- and human-readable form.

  • EU
  • USA
  • MDR
  • IVDR

In one sentence

UDI identifies a medical device by a device identifier (UDI-DI) and production identifier (UDI-PI); required under MDR, IVDR and the FDA UDI rule.

Example

A manufacturer of catheters obtains GS1 identifiers, assigns a Basic UDI-DI to the catheter family and a UDI-DI to each size and package level, prints lot number and expiry date as UDI-PI in a barcode on each pack, and registers the data in EUDAMED.

How it applies

  • UDI-DI and UDI-PI: The UDI-DI identifies the manufacturer and the specific device model or package level; the UDI-PI identifies the production unit, such as lot or serial number, manufacturing or expiry date, or software version.
  • Basic UDI-DI: The primary key of a device model group in EUDAMED. It links the device to the declaration of conformity, certificates, the technical documentation and the SSCP, and does not appear on the label.
  • Issuing entities: GS1, HIBCC, ICCBBA and IFA are designated for the EU. The manufacturer chooses one and follows its coding rules.
  • Carrier: The UDI carrier (for example a barcode or RFID, plus human-readable text) goes on the label and on higher package levels; reusable devices may need a direct marking on the device.
  • Other operators: Importers and distributors verify that devices carry a UDI where required; health institutions and economic operators keep UDI records for certain devices, notably class III implantables.
  • Technical documentation: Keep the UDI assignment rules, the mapping of UDI-DIs to variants and the change criteria that trigger a new UDI-DI under version control; a wrong UDI-DI breaks the link to certificates and vigilance records.

UDI vs. unique product identifier (DPP)

The unique product identifier of the digital product passport serves sustainability and circularity data under the ESPR. The UDI serves patient safety: traceability, recalls and vigilance under MDR and IVDR. Both build on standards such as GS1, but they are separate legal obligations and neither replaces the other.

Compared with the USA

The FDA UDI rule in 21 CFR Part 830 also combines a device identifier and a production identifier; device identifier data go to the Global Unique Device Identification Database (GUDID). A device sold in both markets often uses the same GS1 identifier, but EUDAMED and GUDID are separate databases with different data fields, and the EU Basic UDI-DI has no direct US counterpart.