Hiring or looking for a job in Digital Health? Check out our Digital Health Jobs board

Articles Questions

Updated August 22, 2023

What is a MDR UDI? Unraveling the Importance of Unique Device Identification

Sören Hornof

Check It Out: Free Video Available

While you're gathering your motivation to read yet another article on regulation, let me jump in briefly! We've actually recorded a video on this topic in the meantime. In our videos, we try to be to-the-point and super concrete, so you'll learn exactly what you need to write your own documentation. Check it own below and take a look for yourself!

And if you liked this video, take a look at our UDI video course in which you can watch us literally purchasing UDIs at GS1 and IFA. We explain what we're doing and how you can get your UDIs, too! Much more efficient and cheaper than paying consultants (like us) to do it for you :)

But now, let's move on to the actual article.


What is a UDI in the context of the MDR and FDA?

Short Answer

A Unique Device Identifier (UDI) is a distinctive code assigned to medical devices (and their packaging) to provide them with a unique identity. Similar to a serial number or barcode, a UDI allows for easy identification and traceability of medical devices, e.g. in the EUDAMED database or when communicating with your Notified Body. UDIs can be bought from different number issuing agencies. Those agencies are called GS1, HIBCC, ICCBA and IFA. All of them can also be used in the US for FDA UDIs except IFA.

Long Answer

Both the EU and the FDA require medical devices to have a UDI (Unique Device Identifier). A UDI is a unique alphanumeric code assigned to medical devices, allowing for their clear identification and traceability throughout their lifecycle. Think of it as a digital fingerprint. The UDI comprises two main components: the Device Identifier (DI) and the Production Identifier (PI). And then there’s also the Basic UDI-DI that plays in a league of its own. UDIs are created following an international coding system. In order to participate in this system, you need to register with one of the UDI issuing companies.

Device Identifier (UDI-DI): Yes, this one is really called Unique Device Identifier Device Identifier. It could as well be called “Model Identifier” or “Version Identifier” because this number is assigned to different types of the same device group. You could have a blood pressure monitor that’s available as a professional version and as a direct-to-customer version. Those two models of the same device group would have a different UDI-DI.

Production Identifier (UDI-PI): The UDI-PI provides information about the specific unit of the device, such as its serial or batch number, manufacturing date, or expiration date. It allows for a tracking of single devices of the same device model. This can be handy in the case of a recall when you just want to withdraw devices with certain expiry dates from the market.

Together, the DI and PI create a comprehensive UDI. This UDI is affixed on the device’s label, where it appears in a human-readable format and a machine-readable format (i.e. DataMatrix code or barcode). For devices with only electronic display, no machine-readable UDI is required.

Basic UDI-DI: Its purpose is to group devices with the same intended purpose, risk class, essential design, and manufacturing characteristics. This number described the device group that I mentioned in the description of the UDI-DI. It hardly ever changes, unless you make really fundamental changes. This number can be generated by yourself after you’ve registered with one of the UDI issuing companies.

I’m explaining the entire process of buying, generating and assigning UDIs to medical devices in our new video course. Make sure to check it out!

Where to find the requirements?

The UDI requirements (for the EU) can be found in Article 27 of the Medical Device Regulation (EU MDR) and in Annex VI Part C. If some of the requirements are still unclear after this staggering read, check out the guidelines from the Medical Device Coordination Group (MDCG). The most helpful is probably MDCG 2018-1 which explains when to actually update the Basic UDI-DI and the UDI-DI. And they’ve even created a UDI Helpdesk to help you navigate the jungle of requirements. However, you can also just contact us if you need specific help with your UDIs.

On a slighty different note: You want to get your medical software certified under MDR but don't know where to start? No worries! That's why we built the Wizard. It's a self-guided video course which helps you create your documentation yourself. No prior knowledge required. You should check it out.

Or, if you're looking for the most awesome (in our opinion) eQMS software to manage your documentation, look no further. We've built Formwork, and it even has a free version!

If you're looking for human help, did you know that we also provide some limited consulting? It's limited because we are not many people. We guide startups from start to finish in their medical device compliance.

Congratulations! You read this far.

Get notified when we post something new.

Sign up for our free newsletter.

Sören Hornof

Hi! I am a Pharmacist with great enthusiasm for technology and innovation. Health has always been my major passion and I strongly believe that medical devices will change the world of care. Therefore, I am very happy to be able to work with progressive startups and contribute to this development.


If you have any questions or would like to share your opinion publicly, feel free to comment below. If you'd like to reach out privately, send us a message.

No QMS on this planet will save you from creating crappy software.