The UDI or “Unique Identification Number” Europe (as there is also one in the USA) is one of the new things that come with the new EU MDR 2017/745 and IVDR 2017/746.
This element will be key for the traceability of devices in Europe.
UDI background and regulatory context
Origin
Specifically, the concept of UDI appeared in the IMDRF guidance issued in 2013, which defined the basis of this new technology.
Nowadays, it´s not something new for the Medical Device Industry as it´s also a requirement for products delivered to the US market.
However, manufacturers that are not selling their products in the United States of America will have some work to do.
EUDAMED
The UDI number is important because it will be needed for tracking your product. For that, there is also the European Database for Medical Devices EUDAMED.
I know, this is still not fully in place and we don´t know when it will be exactly as they are postponing the last modules. But the modules that are interesting for us are available. The most important for UDI is the DEVICE REGISTRATION Module.
The UDI will be key as it´s one of the primary numbers to identify your product on this database.
Specifically, the concept of UDI appeared in the IMDRF guidance issued in 2013, which defined the basis of this new technology.
Nowadays, it´s not something new for the Medical Device Industry as it´s also a requirement for products delivered to the US market.
However, manufacturers that are not selling their products in the United States of America will have some work to do.
Understanding the UDI System
What is the UDI or Unique Device Identification?
This is a number that identifies a specific product. On the UDI that is on your product, there are 2 parts which are:
- The UDI-DI
- The UDI-PI
The UDI-DI is the device identifier. It identifies a specific device on your portfolio. This is the static part of the UDI number. It doesn´t change within the same exact product. But we´ll go more deeply on that on the next chapters.
The UDI-PI is the production identifier. It is the dynamic part of the UDI. It tells you about lot number, serial number, manufacturing date, expiration date…
But before that, you need the Basic UDI-DI which identifies a group of product. It´s different from the UDI-DI.
And also the UDI carrier. Ok, I stop.
Are you confused now?
I know it´s not simple to digest all this. So, let´s review each of these ones, one by one. And as I am trying to make it easy for you I´ll illustrate this post with multiple examples.
Example of UDI
As I see that you are confused, I propose that we look at one example.
The UDI can be available in many forms. This is something we will see in the chapter related to the UDI Carrier. It can be a linear bar code as you can see on the example below.
But a legible part should be available. We call it also HRI or Human Readable interpretation.
As said previously, you can see the UDI-DI which is the number after the (01). Each time when you´ll see the 01 between brackets, this means this is the placeholder for the UDI-DI.
Now we arrive at the UDI-PI part. As mentioned, this part can vary as it depends on the production characteristic of the product.
You can identify some numbers in the bracket on the UDI-PI part. Let´s decode them. Each of these numbers is providing specific information about the product:
- (10) is for the lot number
- (11) is for the production date
- (17) defines the expiration date.
- (21) is the serial number.
All these information are dynamic as they change each time you have a new batch or a new expiry date…
Core UDI Identifiers
What is the Basic UDI-DI?
Something that a lot of people were asking is about Basic UDI-DI. I think it created a lot of confusion, so I´ll try to clarify that.
If you are looking at Annex VI Part C of the MDR 2017/745 and IVDR 2017/746, it will provide you with a general definition of what it is. But not so much for me. The other resource that you can check is the MDCG 2018-1 Draft Guidance on Basic UDI-DI. This provides a bit more information that I will summarise here.
The Basic UDI-DI is an identification number that is not for a specific product but for a Group of products.
It has no supply chain value. It´s only used for administrative purposes. If you prefer, it´s like you are creating an identification number for all your Contact lenses. You can have many of them on your portfolio.
One Basic UDI-DI is for devices within the same category:
- Intended purpose
- Risk class
- Essential design
- Manufacturing characteristic
And then when should the Basic UDI-DI appear?
You´ll have it on your:
- Certificates (Notified Bodies)
- Declaration of conformity
- Technical Documentation
- Summary of safety and clinical performance
- Certificate of free sale (Article 60(1) of MDR)
Surprise. This one does not appear on the packaging of the products. It´s really an invisible number for your customers. It´s only for the administration.
And under this Basic UDI-DI, you will have one or many UDI-DI (Specific product identification).
What is the Format of a Basic UDI-DI?
On the MDCG 2019-1 guiding principles of issuing entities rules on Basic UDI-DI, we can see that there are some requirements to follow.
To be as clear and efficient as possible it is required that the Basic UDI-DI format should be as close as possible to the UDI-DI that you’ll see on next chapter.
- Maximum of 25 characters as this is the maximum length of the UDI-DI
- The organization that will provide you the UDI code should also implement a check digit/character. And they should provide an algorithm (to the Commission and the manufacturer) to verify the code.
Security of the code start to increase. The question I am asking myself is if this check digit/character is visible to anyone or if this should be kept secret… Maybe someone to answer on the comments.
Where can I get the Basic UDI-DI?
The UDI, in general, is provided by an official designated entity. I mean, the designated entity will provide you with the tools to create your Basic UDI-DI.
The designation should be done by the Commission if you are looking at Article 24(2).
But let´s look at that in the next chapters.
Decision Tree (Medtech Europe)
What is the UDI-DI?
UDI-DI in case of changes
What is the UDI-PI?
What is the UDI-PI?
UDI-carrier
UDI Format guidance
| Designated entities | Guidance Documents |
|---|---|
GS1 |
|
HIBCC |
|
ICCBBA |
|
IFA |
Implementing UDI for Medical Devices
How to create your UDI-DI & Basic UDI-DI?
Where can I register for the UDI?
Where should I place the UDI on my product?
UDI vs Primary packaging and Secondary packaging
UDI carrier on each level
UDI Checklist
UDI in the EU Regulatory System
UDI and EUDAMED
Legacy devices
EU UDI transition period
Special UDI Cases
UDI for combination products
What is a combination product?
This is a product that combines many regulations.
For example a product that contains both a Medical Device and a Drug. Or a Drug and Cosmetic…
But the product will mainly follow only one regulation. This depends on the intended use.
UDI or not UDI?
If you have Combination products, then you need to understand if UDI is applicable to your product.
On the MDCG 2019-2, you can see the rule to apply.
To summaries the guidance, I can say that if your product is a Medical Device but incorporate a medicinal product, you have to comply with the UDI requirements.
EXAMPLES from the MDCG:
- Catheters coated with heparin or an antibiotic
- Soft tissue fillers incorporating local anaesthetics
- Implantable infusion pump
- Spacer devices for use with metered dose inhalers
- Bone void filler with an antibiotic
- Bone void filler with animal growth factors, where the action of the growth factors is demonstrated to be ancillary to that of the physical filler
But if your product is regulated by the Medicinal Directive 2001/83/EC, the medical device part of it can use or not UDI. This means it’s not mandatory.
EXAMPLES from MDCG:
- Non-reusable autoinjectors containing a medicinal product as integral part
- Nebulizers precharged with a specific medicinal product
- Patches for transdermal drug delivery
- Wound dressings impregnated with an antibiotic, where the primary intended
purpose is to administer the antibiotic to the wound - Bone void filler with animal growth factors, where the action of the growth
factors cannot be demonstrated to be ancillary to that of the physical filler
UDI for standalone software
It can be disturbing to talk about UDI for something that is immaterial. But the EU MDR also provided some information on how to handle this with Softwares. Let’s dig on this.
Which software is on focus?
The only software that can be commercialized alone is on the scope of Annex 6 Part-C paragraph 6 of the EU MDR.
The rule for UDI-DI and UDI-PI
Similar to other products, a software UDI should have the 2 parts (UDI-DI and UDI-PI)
The manufacturing parameters should be displayed on the UDI-PI and the general information about the software on the UDI-DI
Software changes vs UDI change
As you may know, software is constantly maintained. So what to do with the UDI number for each type of changes.
In the case of Minor changes, like some bug correction, usability enhancements without safety purposes, security patches or operating efficiency; you as a manufacturer should change only the UDI-PI.
For example, the lot number or the serial number…
But in case of Major changes, then you need to ask for a new UDI-DI.
Which Major changes require a new UDI-DI?
There are 3 cases defined on the MDR where you’ll need to change the UDI-DI number. Let’s list them:
- The original performance
- The safety or the intended use of the software
- the interpretation of data
All this can include new or modified:
- Algorithms
- Database structures
- operating platform
- architecture or new user interfaces
- or, new channels for interoperability
Where should be placed the UDI number?
This one is interesting as this is a question that a lot of people are asking. Where on software should we write the UDI number?
There are multiple places:
Physical medium
If you deliver your software on a CD or a DVD, you should then place your UDI number on the packaging as HRI and AIDC.
The UDI linked to your system level software should be the same as the one to your packaging level.
Software with User Interface
Software that is not displaying images should be able to transmit the UDI through an application programming interface (API).
Below are some other rules to apply for UDI on a software
HRI or AIDC?
For electronic displays, only the HRI (Human Readable Interface) is required.
AIDC is not required. But if you want to include it, knowing that there is no risk to miss the HRI part, you can.
Application identifiers (AI)
The UDI human readable format should also include the Application Identifiers. This is the standards used by the issuing entity to help identify how this UDI number was created.
Guidance and Resources
Guidance MDCG 2018-1 v2
The European Union issued an update of its MDCG guidance (Medical Device Coordination Group) related to UDI:
The items discussed are:
- The Basic UDI-DI
- Link between Basi UDI-DI and Certificates or Declaration of Conformity
- Changes of UDI-DI
To review the details of this Guidance you can click on the button below.

