UDI Requirements for Medical Devices in Europe — EU MDR Complete Guide

The Unique Device Identification (UDI) system is one of the most significant operational changes introduced by EU MDR. Every medical device placed on the EU market must carry a UDI — a standardised code that uniquely identifies the device and links it to its EUDAMED registration. Getting UDI right is not optional, and the requirements are more specific than many manufacturers expect.

What is a UDI?

A Unique Device Identifier is a series of numeric or alphanumeric characters created through a globally accepted device identification and coding standard. It allows the unambiguous identification of specific medical devices on the market — making post-market surveillance, recalls, and traceability significantly more effective.

The EU UDI system has two components that work together:

• UDI-DI (Device Identifier) — the static part that identifies the specific version or model of your device. This must be registered in EUDAMED before the device goes on the market. A new UDI-DI is required whenever a change is made that could affect the safety, performance, intended use or identification of the device.
• UDI-PI (Production Identifier) — the dynamic part that identifies the specific unit of production. It includes the serial number, lot number, manufacturing date, expiry date, or software version as applicable to your device type.

UDI carrier formats

The UDI must be presented on the label as a UDI carrier — a physical representation of the UDI that can be read both by humans (Human Readable Interpretation or HRI) and by machines (automatic identification and data capture or AIDC). The most common formats are:

• 1D barcodes — GS1-128, HIBC LIC, or ISBT 128 formats
• 2D barcodes — GS1 DataMatrix (most commonly used for medical devices)
• RFID — required for active implantable devices and recommended for high-value reusable devices

UDI application deadlines by device class

UDI requirements have been phased in by device class under EU MDR:

• Class III and implantable Class IIb devices — UDI on label and EUDAMED registration required from May 2021
• Class IIa and non-implantable Class IIb devices — UDI on label required from May 2023
• Class I devices — UDI on label required from May 2025
• Reusable surgical instruments — UDI on label required from May 2027

EUDAMED UDI database registration

Every UDI-DI must be registered in the EUDAMED UDI database before the device is placed on the EU market. This is a separate registration from your actor registration — you need both your SRN (company registration) and your UDI-DI registration completed before your first shipment.

As your EU Authorized Representative, NordMDR AB handles your EUDAMED actor registration and links your UDI-DI registrations to your account. We ensure all required data fields are completed correctly — incorrect or incomplete EUDAMED UDI data is one of the most common causes of delayed market entry.

What information must be in the EUDAMED UDI database

For each device, the following core data must be submitted to EUDAMED:

• Basic UDI-DI and all associated UDI-DIs
• Device name and trade name
• Risk classification
• Reference/catalogue number
• Clinical size information where applicable
• Single use / maximum number of reuses
• Sterility information
• MRI safety information where applicable
• Implantable device flag
• EU Authorized Representative details

Common UDI mistakes that delay EU market entry

• Using US FDA UDI numbers directly — FDA UDIs and EU UDIs use different issuing agencies and formats. Your FDA UDI is not automatically valid for EU purposes.
• Not updating UDI-DI after device changes — any change that affects safety, performance, or identification requires a new UDI-DI registration.
• Missing Human Readable Interpretation — the UDI must be readable both by machine and by humans. A barcode alone without the HRI text below it is non-compliant.
• Incorrect EUDAMED data — EUDAMED submissions with errors or missing mandatory fields are rejected, delaying your market entry.