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 Medical Device       
Medical Device Coordination Group Document    MDCG 2018-1 v3   
 
 
 
 
       
   MDCG 2018-1 v3  
Guidance on BASIC UDI-DI  
      and changes to UDI-DI            
 
             March 2020 
 
  
 
This document has been endorsed b y the Medical Device Coordinat ion Group (MDCG) established by 
Article 103 of Regulation (EU) 2017/745. The MDCG is composed o f representatives of all Member 
States and it is chaired by a representative of the European Co mmission. 
The document is not a European Commission document and it canno t be regarded as reflecting the 
official position of the European Commission. Any views express ed in this document are not legally 
binding and only the Court of Justice of the European Union can  give binding interpretations of Union 
law.   
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 Guidance on BASIC UDI-DI and changes to UDI-DI 
Introduction 
The new Medical Device Regulations (EU) 2017/745 and (EU) 2017/746 introduce a 
Unique Device Identification (UDI) system for medical devices.  
Main provisions related to the establishment of the UDI system are contained in 
Chapter III and Annex VI of the two medical device Regulations.  
The main features of the UDI system and relevant obligations for operators will be 
provided in a dedicated Q/A paper to be published by the Commission in spring 2018.  
This guidance is intended to provide a clarification on the notion of Basic UDI-DI, its 
use in relevant documentation and the factors triggering UDI-DI changes.   
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The Basic UDI-DI 
The Basic UDI-DI is the main key in the database and relevant documentation (e.g. 
certificates, declaration of conformity, technical documentation and summary of safety and clinical performance) to connect devices with same intended purpose, risk class and essential design and manufacturing characteristics.  
It is independent/separate from the packaging/labelling of the device and it does not 
appear on any trade item.  
Any Basic UDI-DI shall identify the devices (group) covered by that Basic UDI-DI in a 
unique manner. 
Link with between Basic UDI -DIs and certificates or declaration of conformity 
In accordance with Annex XII of the medical device Regulations, the scope of the 
certificates shall unambiguously identify the device or devices covered. The scope of EU technical documentation assessment certificates, EU type-examination certificates and EU product verification certificates shall include, together with the Basic UDI-DI, a clear identification, including the name, model and type, of the device or devices, the intended purpose, as included by the manufacturer in the instructions for use and in relation to which the device has been assessed in the conformity assessment procedure and the risk classification. 
Each of the abovementioned certificates shall identify and cover all devices 
associated with the same Basic UDI-DI, that is referred to in that certificate.  
The association between different Basic UDI-DIs, where applicable, shall be 
identified through the technical dossiers.  
In accordance with Annex IV of the two Regulations, the declaration of conformity 
shall contain the Basic UDI-DI and the product and trade name, product code,  
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 catalogue number or  other unambig uous reference allowi ng identif ication and 
traceability of the device covered by the EU declaration of conformity. 
Changes of UDI-DI 
A new UDI—DI shall be required whenever there is a change that could lead to 
misidentification of the device and/or ambiguity in its traceability. In particular, a new UDI-DI shall be required in the case of any change of the following elements: 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
1 2. 
 A UDI-DI shall be associated with one and only one Basic UDI-DI.  
 
  
Regarding changes to the specific data elements listed below
3, the following 
considerations should be noted: 
1. Is the Device Directly Marked (Yes/No) 
The database design will force the creation of a new UDI-DI only if there is a change 
from Yes to No and not vice versa for this data element.  
 
2. Manner in which production of the device Is controlled (expiry date or 
manufacturing date, lot number, serial number, software identification)  - Type of UDI-PI  
As long as there is no change to the la bel, a change to this data element will not 
require the allocation of a new UDI-DI. 
                                                           
1  It should be noted that a new regulatory decision classifying  an existing product as CMR/Endocrine 
disruptor might not result in a new UDI-DI for products already  containing that substance. The decision on 
whether to assign a new UDI-DI should be based on the conformit y assessment of the product with regard 
to the impact of the information provided and the significance of the change. 
2  Specific attention shall be paid to the fact that changes of colour or language might also require a new UDI-
DI when those changes might lead to misidentification of produc t or change the product 
safety/performance. For example:  
A- Change of colour coding of e.g. connectors, latex-free surgi cal gloves, blood tubes  
B- Two identical self-testing de vices, that exist in parallel a nd cannot be substitute d due to local labelling 
requirements (IVD Article 10(10) of Regulation 746/2017), requi res different UDI-DIs 
Specifications of EU designated issuing entity should be used a s a reference source to identify other 
possible examples.  
3 Please refer to Guidance UDIWG 2018-1 on "UDI database. Defini tions, descriptions and formats of the UDI 
core elements’  available at https://ec.europa.eu/docsroom/documents/28669   
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WARNING: This guidance does not address requirements for reprocessed devices, 
systems or procedure packs, software, Annex  XVI, nor for cases of parallel trade or 
own brand labelling. Specific requirement s for those products are addressed in 
specific guidance.