How to understand Basic UDI-DI and UDI

The Medical Device Regulations (EU 2017/745, EU 2017/746) introduce the Unique Device Identification (UDI) system to unambiguously identify medical devices within the global supply chain.

The main features of the UDI system are outlined in Art. 27 to 31 and Chapter III and Annex VI of the regulations, but further guidance is expected from the EU Authorities.

The new system will be applied to all medical devices (except custom-made and performance study/investigational devices) and is substantially based on internationally recognised principles and EU harmonized standards, notably by using definitions that are compatible with those used by major trade partners.

What is the Basic UDI-DI

Unlike the US FDA regulation, the EU regulations introduce a new identifier, the “Basic UDI-DI” intended to group devices with the same intended purpose, risk class, essential design and manufacturing characteristics. Basic UDI-DI is a numeric or alphanumeric code.

The Basic UDI-DI is the main access key for device-related information in the EUDAMED database and should be referenced in relevant documentation [e.g. certificates (including certificate of free sale), EU declaration of conformity, technical documentation, summary of safety and (clinical) performance) and vigilance and FSCA notification form].

Basic UDI-DI shall not appear on the device label or packaging or on any trade item.

Any Basic UDI-DI shall identify the devices (group) covered by that Basic UDI-DI in a unique manner.

What is the UDI?

The UDI is a series of numeric or alphanumeric characters that is created through a globally accepted device identification and coding standard. It allows the unambiguous identification of a specific medical device on the market

1.       device identifier(UDI-DI), a fixed code specific to a version or model of a device.

2.       production identifier (UDI-PI), a variable code related to production data of the device, such as lot/batch number, expiry date, manufacturing date, etc.

The UDI-DI will be determined by elements such as name or trade name, device version or model, labelled as single use, packaged sterile, need for sterilization before use, quantity of devices provided in a package, critical warnings or contra-indications (e.g. containing latex or DEHP), CMR/Endocrine disruptors and so forth. Any change to one of more of these elements will therefore make a change of UDI identifier necessary.  A UDI-DI shall be associated with one and only one Basic UDI-DI.

The UDI-DI must be applied to the medical device label, its packaging and, in some cases, the device itself.

Responsibility for assigning UDI

The manufacturer of the medical device is responsible for complying with all UDI related requirements. This includes the assignment of the UDI (and Basic UDI-DI), the UDI (and Basic UDI-DI) registration in the EUDAMED database and the placement of the UDI carrier on the label of the device or on its packaging or, in case of reusable devices, on the device itself (direct marking).

Systems and procedure packs shall undergo a UDI registration, as described in Article 29(2) of MDR.

The producer of system or procedure pack – that is not a custom-made device – shall assign to the system or procedure pack a Basic UDI-DI and shall provide it to the EUDAMED database together with the other relevant core data elements, as listed in the MDCG document.


The obligation for UDI assignment applies as from the date of application of the two new Regulations, i.e. 26 May 2020 for medical devices and 26 May 2022 for In Vitro diagnostic medical devices.

The obligation for submission of UDI data in the EUDAMED database is postponed due to the delay of EUDAMED announced by the European Commission in October 2019. As it stands today, the EUDAMED will be fully operational in May 2022, and it is expected that the mandatory submission of UDI data for medical devices shall be performed in the 18 months after that date.

It shall be noted that, provided that EUDAMED is fully functional, at any time after 26 May 2020 for medical devices and 26 May 2022 for In Vitro diagnostic medical devices, the full registration of devices (Article 29 of MDR and Article 26 of IVDR) remains a pre-condition for the possible registration of their relevant serious incident in EUDAMED.


Deputy Manager of VIP Department

September 11, 2019

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