EUDAMED FAQ: Basic UDI-DI, UDI-DI and issuing entities

By the eudaflow team · Published: 2 October 2026

How legacy devices are identified, which devices can share a Basic UDI-DI and what EUDAMED checks in codes from GS1, HIBCC, ICCBBA and IFA.

The identifiers decide how devices are grouped and found in EUDAMED, and they are hard to correct afterwards. These are the questions we see most. Each answer names its official source.

How is a legacy device identified without a Basic UDI-DI?

A legacy device gets a EUDAMED DI instead of a Basic UDI-DI. The EUDAMED DI is the equivalent of the Basic UDI-DI. If the device has no UDI-DI, EUDAMED also generates a EUDAMED ID, which is the equivalent of the UDI-DI.

The formats are fixed:

If the manufacturer already has a UDI-DI for the legacy device, it can use that as the device identifier. EUDAMED builds the EUDAMED DI by putting B- in front of the UDI-DI.
If there is no UDI-DI, the EUDAMED DI has a strict format that starts with B-. The EUDAMED ID has the same value but starts with D- instead of B-.

Legacy devices are not subject to the UDI requirements of the MDR and IVDR. The definition of a legacy device is in MDCG 2021-25 Rev.1 for the MDR and MDCG 2022-8 for the IVDR.

Sources: EUDAMED Information Centre, identification details of legacy devices, when a UDI-DI exists and when it does not; Commission infographic on legacy identifiers; Commission Q&A, Q7 and Q8. Last checked 29 September 2026.

Which devices can share one Basic UDI-DI?

Devices that match on three points: intended purpose, risk class, and the essential design and manufacturing characteristics. The Commission's guidance MDCG 2018-1 and the EUDAMED Information Centre both give these criteria. The EUDAMED data dictionary calls the Basic UDI-DI the primary identifier of a device model.

How it relates to the UDI-DI:

A Basic UDI-DI has at least one UDI-DI, and several UDI-DIs can share the same Basic UDI-DI.
Each UDI-DI belongs to exactly one Basic UDI-DI.
In EUDAMED you cannot register a Basic UDI-DI without a UDI-DI. Every Regulation device needs both.
The Basic UDI-DI is not on the label or the packaging. It is used in the database and in documents such as certificates and declarations of conformity.

Sources: MDCG 2018-1 Rev.4; Information Centre, categorisation of devices; UDI Devices data dictionary; UDI Devices user guide. Last checked 29 September 2026.

GS1, HIBCC, ICCBBA or IFA: what does EUDAMED check in a code?

It depends on the code. The Commission designated four issuing entities, GS1, HIBCC, ICCBBA and IFA, and renewed the designations until 27 June 2029. EUDAMED then treats their codes differently:

Basic UDI-DI: EUDAMED validates the format for every issuing entity and stops you if the code is not valid. The MDCG guidance says a Basic UDI-DI must include a check digit or character based on the issuing entity's algorithm.
UDI-DI from GS1: EUDAMED expects a 14-digit code including the check digit, and validates it. The last digit of a GTIN is a check digit calculated from the other digits.
UDI-DI from HIBCC, ICCBBA or IFA: the business rules check the format of the UDI-DI and of similar codes only when the issuing entity is GS1. They describe no format check for the other three.

That gap is worth knowing. In our own Playground test, a HIBCC secondary UDI-DI with a valid check character but a labeler code that belongs to nobody was accepted. Accepted by EUDAMED does not mean correct, so check these codes against the issuing entity's own rules.

Two details for HIBC codes. The primary data structure on the label ends with a check character, but the HIBC standard says the check character is not transmitted or stored in the database when data are exchanged electronically. The HIBC Basic UDI-DI is different: it always ends with a two-character check value.

For the identifiers of legacy devices EUDAMED sets the issuing entity to EUDAMED automatically.

Sources: Commission, Unique Device Identifier; Information Centre, Basic UDI-DI information and Basic UDI-DI generators; UDI Devices business rules, BR-UDID-003 and BR-UDID-644; UDI Devices user guide; MDCG 2019-1; GS1 check digit calculator; HIBC standard 2.6; HIBC Basic UDI-DI; our Playground test report. Last checked 29 September 2026.

Sources and how we checked

Every statement above is tied to a quote in a claims register, and a script compares each quote with the current text of its source before we publish. This page is general information, not legal advice.