Implementing Master UDI-DIs: Key Insights from MDCG 2025-7

Dr Will Brambley
A vision testing device.

The latest guidance from the Medical Device Coordination Group (MDCG), published as MDCG 2025-7, introduces the implementation of Master Unique Device Identification - Device Identifiers (UDI-DIs) for a number of highly individualised devices.

The use of a Master UDI-DI aims to strengthen and enhance the traceability and recording of UDIs. Master UDI-Ds allow the grouping of highly individualised devices with specific design similarities under a common identifier to be assigned and registered on Eudamed. This should effectively eliminate the need for a manufacturer to have dozens if not hundreds of UDI-DIs for very similar devices by unifying them under one Master UDI-DI.

Devices Addressed by MDCG 2025-7

The devices covered by this guidance are:

  • Contact lenses
  • Spectacle frames
  • Spectacle lenses
  • Reading spectacles

According to MDCG 2021-24:

  • Corrective contact lenses are classified as Class IIa (short-term use) or Class IIb (long-term use) medical devices.
  • Spectacle frames, spectacle lenses, and reading spectacles are classified as Class I medical devices.

Implementation Deadlines

MDCG 2025-7 aims to clarify the timelines of implementation of Master UDI-DIs for these devices, as well as the obligations of manufacturers relating to Eudamed and vigilance reporting.

Key dates include:

  • Manufacturers must place UDI carriers on the label of a device and on all higher levels of packaging for Class I devices from 26 May 2025
  • Manufacturers must use the UDI/Device registration module in Eudamed by Q1 2026
  • Master UDI-DIs become mandatory for contact lenses from 9 November 2026
  • Master UDI-Dis become mandatory for spectacle lenses and reading glasses from September 2028
  • If a manufacturer has assigned a Master UDI-DI to a device before Q1 2026, they must use it for vigilance reporting.

Moving Forward with Master UDI-DIs

The introduction of Master UDI-DIs marks a step forward in improving the traceability and administrative workload of highly individualised medical devices. By allowing manufacturers to group similar products under a single identifier, the guidance aims to reduce burden while maintaining safety and compliance standards. Manufacturers of these devices should take note of the implementation timelines and obligations, particularly around Eudamed registration and vigilance reporting, to ensure that they can prepare effectively for full compliance.

Back to top

Related articles

  1. A person studying at a desk with pad and paper.

    In the World of Regulatory Writing: 5 Lessons Learned

    Let’s break down some key lessons learned from the writing process and share practical tips to navigate them with clarity (and your sanity) intact.

    Kamiya Crabtree Kamiya Crabtree Regulatory Medical Writer
  2. Poster frame for video with Sue Kemp.

    Do you have the clinical evidence you need to support regulatory approval?

    Sue Kemp makes the case for implementing clinical strategy from day one.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  3. An actual conventional UK passport.

    A New Era for NHS Innovation: ‘Innovator Passports’

    A digital fast-track system aims to transform how new medical technologies are adopted across the NHS, cutting red tape and accelerating access to medtech.

    Kamiya Crabtree Kamiya Crabtree Regulatory Medical Writer
  4. LinkedIn live webinar poster.

    From Idea to Approval: Get MDR Ready With Our LinkedIn Live

    An upcoming LinkedIn Live session with Dr. Zhong Wei Khor tailored specifically for healthtech founders.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  5. A man crosses a high-wire across a forest.

    The Never-Ending Document Updates: Navigating Changing Regulations

    Just because you’ve submitted a document, it doesn’t mean the work is done. Clinical Evaluation Reports, Risk Management Files or PMS plans will all need updating.

    Kamiya Crabtree Kamiya Crabtree Regulatory Medical Writer
  6. A judges gavel sat infront of a Union Jack flag.

    UK Medical Device Regulations Set for Major 2026 Update

    The UK government is preparing to introduce a second major update to the regulatory framework for medical devices, with new pre-market requirements expected to come into effect in 2026.

    Dr Simon Cumiskey Dr Simon Cumiskey Senior Lead Medical Writer
  7. Video poster frame for Episode 3 of our series.

    Clinical Evaluation Masterclass: It is not clear that any systematic search methods were used for the literature review – Episode 3

    Addressing non-conformities isn’t just about avoiding negative outcomes; it’s about building a robust, evidence-based foundation.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  8. A woman writes notes at her desk.

    Regulatory Writing Deadlines: The Pressure to Get It Right the First Time

    Anyone who’s worked in the medical device industry knows that regulatory deadlines aren’t just part of the process—they define it.

    Kamiya Crabtree Kamiya Crabtree Regulatory Medical Writer
  9. Medical phone software being used to communicate with a monitor placed on a mans skin.

    IEC 62366-1:2015 Demystified – Essential Usability Testing for Medical Devices

    What should be included in a Usability Engineering File? What steps do you need to take to ensure compliance and meet standards?

    Kamiya Crabtree Kamiya Crabtree Regulatory Medical Writer
  10. Video poster frame for Episode 2 of our ongoing series.

    Clinical Evaluation Masterclass: Appraisal of literature sources has not been conducted properly - Episode 2

    Our ongoing series covers one of the most frequent reasons for CER rejection: a poor appraisal of literature sources.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  11. A lone figure navigates a rocky coastline.

    Navigating CAPA Terminology: Key Terms for Medical Device Professionals

    We define and explain the language required to work within a Quality Management System (QMS).

    Kamiya Crabtree Kamiya Crabtree Regulatory Medical Writer
  12. Video poster frame for Episode 1 of our new series.

    Clinical Evaluation Masterclass: Overcoming Non-conformities - Episode 1

    In this series, we work step-by-step through common Non-Conformities to ensure you are always ahead of possible challenges on the way to MDR approval.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  13. A man carefully steps across a cliff-face. An analogy for assessing risk.

    Top 5 Common Pitfalls to Avoid During Risk Assessment

    Learn how to sidestep costly mistakes which manufacturers commonly make. From hazard ID to post-market surveillance, we help you improve safety and speed up approvals.

    Kamiya Crabtree Kamiya Crabtree Regulatory Medical Writer
  14. A label maker printing bar-code labels.

    Labelling 101: A Comprehensive Overview for Medical Device Manufacturers

    Labelling and packaging are critical elements to ensuring safety, compliance, and ease of use.

    Kamiya Crabtree Kamiya Crabtree Regulatory Medical Writer
  15. An illustration of a brain-shaped object on an abstract background.

    European Commission Guidelines on Prohibited Artificial Intelligence Practices

    Summary of the 8 AI practices prohibited by the EU 2024/1689 artificial intelligence (AI) Act.

    Dr Clare Dixon Dr Clare Dixon Regulatory Specialist
  16. A compass being used to navigate across mountainous countryside.

    Navigating Non-Conformities in Technical Documentation

    We explore how to manage non-conformities effectively and implement Corrective and Preventive Actions (CAPAs).

    Kamiya Crabtree Kamiya Crabtree Regulatory Medical Writer
  17. A photograph of a literal maze that we're using as a clever metaphor.

    Mastering the EU MDR: Essential Steps for Compliance-Ready Docs

    If you're uncertain about the readiness of your EU MDR documentation, this article provides an overview of the essential steps to ensure you’re on track.

    Kamiya Crabtree Kamiya Crabtree Regulatory Medical Writer
  18. An illustration showing scientists at work.

    A Guide to Electronic Instructions for Use (eIFU)

    Electronic Instructions for Use (eIFUs) are set to revolutionise how medical device instructions are delivered. We explore what this means for you.

    Dr Will Brambley Dr Will Brambley Lead Medical Writer
  19. Two helicopters look as if they are about to collide: An analogy for risk.

    Navigating Risk Management Requirements under the EU MDR

    This is a cornerstone of EU MDR 2017/745, requiring a continuous, well-documented approach. We unpack key requirements and provide actionable strategies.

    Dr Peter Boxall Dr Peter Boxall Lead Medical Writer
  20. A doctor operates a tablet computer.

    Beyond the Acronyms: Understanding SaMD and SiMD

    As software advancements continue, the line between traditional hardware-centric medical devices and software-driven solutions becomes increasingly blurred.

    Kamiya Crabtree Kamiya Crabtree Regulatory Medical Writer
  21. A team of profesional-looking people sit around a table, congratulating themselves.

    Extending the Validity of your IVDD Certificates – Key Dates

    The EU and the MHRA have extended the validity of IVDD certificates, allowing you more time to transition to the IVDR. We explain what this means for manufacturers.

    Kamiya Crabtree Kamiya Crabtree Regulatory Medical Writer
  22. A team of profesional-looking people sit around a table, congratulating themselves.

    GSPR 1: A New Era of Performance with Safety at the Core

    This regulation emphasizes risk management, durable design & biocompatibility to ensure medical devices are safe and effective. GSPR 1 protects users while driving innovation in medical technology.

    Kamiya Crabtree Kamiya Crabtree Regulatory Medical Writer

  23. Cybersecurity Vulnerabilities in Medical Devices: FDA Alerts on Contec and Epsimed Monitors

    Patients can be exposed to risks when devices are online. We explore implications for EU MDR/IVDR cybersecurity requirements, including MDCG guidance

    Dr Clare Dixon Dr Clare Dixon Regulatory Specialist
  24. A futuristic-looking factory full of labelled cardboard boxes.

    Decoding UDI: Your Ultimate Guide to Smarter Medical Device Labelling

    The Unique Device Identifier (UDI) ensures medical device traceability and compliance. We break down its structure, Device Identifier (UDI-DI), Production Identifier (UDI-PI) and its role in EUDAMED.

    Kamiya Crabtree Kamiya Crabtree Regulatory Medical Writer
  25. A medical team discuss performance data at their desktop computer.

    Key Updates for Navigating EMDN: MDCG 2024-2 Rev.1 & 2021-12 Rev.1

    Release of the updated guidance helps manufacturers navigate the EMDN system for accurate device classification, ensuring market access.

    Ron Sangal Ron Sangal Lead Medical Writer
  26. A dated monitor for medical equipment.

    Understanding Clinical Evidence Requirements with MDCG 2020-6

    How can manufacturers ensure legacy devices meet MDR's stringent requirements? Discover how MDCG 2020-6 guidance simplifies the path to compliance.

    Dr Clare Dixon Dr Clare Dixon Regulatory Specialist
  27. A stethoscope laid on a desk of regulatory documentation.

    Clinical benefits of an in vitro diagnostic medical device

    How to determine the clinical benefit of an IVD and successfully incorporate it into regulatory documentation.

    Dr Gayle Buchel Dr Gayle Buchel Chief Medical Writer
  28. EU flags

    Regulation (EU) 2024/1860 - Its impact on EU MDR and IVDR

    How does the recent Regulation (EU) 2024/1860 amendment affect the EU MDR & IVDR?

    Shona Richardson PhD Shona Richardson PhD Regulatory Project Lead
  29. EU flag

    MDCG 2024-10 - Orphan medical devices

    How to apply MDR pre-market clinical evidence requirements to medical devices intended for limited usage.

    Dr Simon Cumiskey Dr Simon Cumiskey Senior Lead Medical Writer
  30. Considering a medical device's intended purpose

    A medical device's intended purpose - what is the point?

    How do you define intended purpose, indication for use, intended clinical benefits, and claims?

    Dr Simon Cumiskey Dr Simon Cumiskey Senior Lead Medical Writer
  31. Mantra Systems presents EnableChat, your AI-powered MDR & MDCG chatbot

    EnableChat - Your AI-powered MDR and MDCG chatbot

    Search the MDR and MDCG documents in seconds by asking EnableChat your questions.

    Dr Simon Cumiskey Dr Simon Cumiskey Senior Lead Medical Writer
  32. Searching adverse event databases for vigilance data

    Staying vigilant - A guide to searching for adverse events data

    We discuss the pros and cons of existing adverse event databases for vigilance data searching.

    Dr Simon Cumiskey Dr Simon Cumiskey Senior Lead Medical Writer
  33. A doctor reading an SSCP document with a patient

    What is Summary of Safety and Clinical Performance (SSCP)?

    We explain what the SSCP is, when you'll need it and what its objectives are.

    Sandra Gopinath Sandra Gopinath Chief Regulatory Officer
  34. A pile of question marks

    Medical Device 'Significant Changes' – Navigating EU MDR Article 120(3) using MDCG 2020-3 rev. 1

    Understand what changes to your medical device are considered 'significant' under EU MDR (2017/745).

    Shen May Khoo Shen May Khoo Regulatory Project Lead
  35. A signpost giving unsure directions

    MDR or IVDR - A sibling rivalry?

    A guide to easily understanding whether your device is a medical device or an in vitro diagnostic medical device (IVD).

    Dr Gayle Buchel Dr Gayle Buchel Chief Medical Writer
  36. An EU and UK flag

    What the latest Brexit U-turn means for CE Marking of medical devices in Great Britain

    Will Great Britain continue to allow the use of the CE mark for medical devices beyond the 2024 deadline?

    Dr Hanna Gul Dr Hanna Gul Lead Medical Writer
  37. A woman writing her own medical device regulation documentation

    Gain confidence, reassurance and control over your EU MDR strategy

    Find out how to build your own technical files within a guided framework while minimising financial outlays.

    Dr Gayle Buchel Dr Gayle Buchel Chief Medical Writer
  38. Racing to achieve MDR compliance

    Still racing to achieve MDR compliance? A transition period update

    On January 6th 2023, the EU commission has adopted the proposal to extend the transition rules of the EU MDR.

    Sandra Gopinath Sandra Gopinath Chief Regulatory Officer
  39. A 7-step guide to navigating regulatory requirements for medical device start-ups

    A medical device regulations guide for start-up companies

    We present a 7-step guide to navigating regulatory requirements on a budget.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  40. An update on UKCA Marking of Medical Devices

    UKCA Marking of Medical Devices – An update on the status quo

    We review recently updated requirements for UKCA marking and what it means for your regulatory strategy.

    Dr Hanna Gul Dr Hanna Gul Lead Medical Writer
  41. How to choose a CER writer for your MDR Clinical Evaluation

    Choosing a CER writer for your MDR Clinical Evaluations

    We've compiled a list of considerations that will help you make the right choice when choosing a CER writer.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  42. Achieving MDR Compliance for Class I medical devices

    How to achieve MDR Compliance for Class I medical devices

    We outline a strategy for the regulatory compliance of Class I medical devices.

    Sandra Gopinath Sandra Gopinath Chief Regulatory Officer
  43. Literature Search, SOTA Review and Clinical Evaluation

    Literature Search, SOTA Review process and Clinical Evaluation

    We help to demystify the process of systematic search & review of literature for Clinical Evaluation.

    Sandra Gopinath Sandra Gopinath Chief Regulatory Officer
  44. Literature Search Protocols & SOTA Reviews for medical devices and what to know before you start

    Literature searches and reviews for medical devices - what to know before you start

    We explain what you should know before beginning a literature search & review for your medical device.

    Sandra Gopinath Sandra Gopinath Chief Regulatory Officer
  45. Five useful resources when writing a medical device CER

    Five useful resources when writing a medical device CER

    We outline five of the most useful and trustworthy Clinical Evaluation Report writing resources.

    Victoria Cartwright Victoria Cartwright Relationship Manager
  46. Avoid pitfalls when writing a Clinical Evaluation Report

    Five common pitfalls when writing a Clinical Evaluation Report

    We illustrate five pitfalls when writing CERs and give you some tips to overcome them.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  47. How to make a medical device equivalence claim under the MDR

    Five tips for making a medical device equivalence claim under the MDR

    We'll show you what to keep in mind with regards to equivalance and Clinical Evaluation.

    Sandra Gopinath Sandra Gopinath Chief Regulatory Officer
  48. Keeping medical devices in market and maintaining CE-marks - a guide to effective data collection

    Keeping medical devices in market and maintaining CE-marks

    The 4 golden rules to drive regulatory compliance with PMCF and vigilance data collection.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  49. How PMCF goes beyond simple compliance - improving products and engaging customers

    How PMCF goes beyond simple compliance

    The wider benefits of a well-designed PMCF system include improving your products and your relationship with your clients.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  50. PMCF systems for medical devices

    Why you'll almost certainly need a PMCF system for your medical devices

    We tell you what to be aware of under the EU MDR regarding PMCF and your medical devices.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  51. Ensure medical device regulatory compliance of your devices through Brexit

    The impact of Brexit on medical device regulatory compliance

    How to ensure regulatory alignment of your devices in the territories affected by Brexit.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  52. Use medical device regulatory consulting services to supercharge your MDR transition

    Is outside consulting support the answer to your MDR transition?

    Getting ready for the MDR is a demanding process. Outsourcing might be your solution.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  53. Increasing data entry compliance in PMCF studies

    Increasing data entry compliance in PMCF studies

    5 methods every medical device manufacturer should know to improve their Post-Market Clinical Follow-up studies.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  54. Why medical doctors can drive MDR compliance

    Why medical doctors can drive MDR compliance

    Working with the MDR requires knowing how to work with clinical evidence. Medical doctors are perfectly positioned to meet this requirement.

    Victoria Cartwright Victoria Cartwright Relationship Manager
  55. Software as a Medical Device

    Software as a Medical Device

    Unless you have spent time working with medical device legislation in the past, the idea that software could be a medical device may be rather unexpected.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  56. clinical investigator for pmcf eu mdr compliance

    Ensuring that clinical investigations work in practice

    How can medical device manufacturers ensure valid clinical investigations when access to medical expertise remains limited?

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  57. Coronavirus and medical device regulations

    Relaxing medical device regulatory requirements during a healthcare crisis

    During the coronavirus pandemic, how far should we go when relaxing medical device regulatory requirements?

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  58. The new MDR compliance challenge

    The new MDR compliance challenge

    Across the industry, medical device companies are facing challenges in meeting the demands of the new Medical Device Regulations (MDR) 2017/745 framework.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer
  59. Sources of Real World Evidence for MDR compliance

    Sources of Real World Evidence for MDR compliance

    At Mantra Systems our objective is to make sure that our clients choose the method of real world data harvesting that is right for them.

    Dr Paul Hercock Dr Paul Hercock Chief Executive Officer

More articles

Do you need support with your medical device approval strategy?

Contact us today