The EU declaration of conformity is usually the shortest document in a medical device file, and it is often the last one written. That order makes sense, but the importance doesn't follow the page count. Under the Medical Device Regulation (EU) 2017/745 (MDR), the declaration is the manufacturer's statement that the requirements of the Regulation have been fulfilled for the device it covers, and by drawing it up the manufacturer assumes responsibility for that compliance (MDR Article 19). For software and AI-enabled devices, which change far more often than hardware, keeping that statement accurate is an ongoing task rather than a launch-day signature.
This guide covers what the declaration is, what Annex IV requires it to contain, how it differs between the EU and Great Britain, and how to keep it current for SaMD.
The legal role of the declaration
Article 10(6) MDR sets the sequence. Once compliance with the applicable requirements has been demonstrated through the applicable conformity assessment procedure, the manufacturer draws up an EU declaration of conformity under Article 19 and affixes the CE marking under Article 20. The declaration comes after the evidence, not before it.
Article 19 then sets four rules:
The declaration states that the requirements of the MDR have been fulfilled for the covered device, contains at least the information in Annex IV, and is translated into the official Union language or languages required by the Member States where the device is made available (Article 19(1)).
The manufacturer must continuously update it (Article 19(1)).
Where other Union legislation also requires an EU declaration of conformity, a single declaration is drawn up covering all applicable Union acts, with the information needed to identify each one (Article 19(2)).
By drawing up the declaration, the manufacturer assumes responsibility for compliance with the MDR and all other Union legislation applicable to the device (Article 19(3)).
The IVDR follows the same structure through Article 17 and its own Annex IV (IVDR).
For class I devices, Article 52(7) MDR is explicit: the manufacturer declares conformity by issuing the declaration after drawing up the technical documentation in Annexes II and III. For sterile, measuring and reusable surgical class I devices, and for all higher classes, the notified body's procedure has to be completed first.
The declaration is not the technical documentation. It sits on top of it. If the technical documentation doesn't support the statement, the declaration is wrong, regardless of how well it is formatted. The manufacturer must keep the declaration, the technical documentation and any relevant certificates available to competent authorities for at least 10 years after the last device covered by the declaration is placed on the market, or 15 years for implantable devices (Article 10(8) MDR).
What Annex IV requires
Annex IV MDR lists the minimum content. Every item is mandatory where it applies:
| # | Annex IV content | Practical note for SaMD |
|---|---|---|
| 1 | Name, registered trade name or trade mark of the manufacturer and, where applicable, its authorised representative; SRN if issued; registered place of business | Use the legal entity that is the manufacturer, not a trading name or the parent group |
| 2 | Statement that the declaration is issued under the sole responsibility of the manufacturer | Fixed wording, but it must be present |
| 3 | Basic UDI-DI (Annex VI Part C) | Must match the Basic UDI-DI in EUDAMED and the technical documentation |
| 4 | Product and trade name, product code, catalogue number or other unambiguous reference, and the intended purpose | Except for the product or trade name, identification may be provided by the Basic UDI-DI |
| 5 | Risk class under Annex VIII | For software, usually driven by Rule 11 |
| 6 | Statement of conformity with the MDR and any other Union legislation that requires a declaration | Lists every applicable Union act in one document |
| 7 | References to any common specifications used | Only where conformity is declared against a CS |
| 8 | Where applicable, the notified body name and number, the conformity assessment procedure and the certificate(s) | Must match the certificate exactly |
| 9 | Where applicable, additional information | Optional |
| 10 | Place and date of issue, name and function of the signatory, on whose behalf they signed, and signature | The signatory must have the authority to bind the manufacturer |
The Basic UDI-DI deserves particular care. The European Commission describes it as the main access key for device-related information in the UDI database, referenced in certificates, the EU declaration of conformity, the technical documentation and the summary of safety and performance (European Commission factsheet). A mismatch between the Basic UDI-DI on the declaration and the one registered in EUDAMED is easy to find and hard to explain. Our EUDAMED and UDI registration checklist covers how to keep those records aligned.
One declaration, several Union acts
Article 19(2) requires a single declaration where a device is also subject to other Union legislation that requires its own EU declaration of conformity. For digital health products, the relevant one to watch is the AI Act. Article 47 of Regulation (EU) 2024/1689 requires providers of high-risk AI systems to draw up an EU declaration of conformity, and also provides for a single declaration where the system is subject to other Union harmonisation legislation that requires one (AI Act). When those obligations apply to an AI-enabled medical device, the MDR declaration and the AI Act declaration should be combined rather than maintained as two documents that can drift apart.
The practical point is the same for any combination. The declaration has to name each legal act it relates to, and the technical documentation has to contain the evidence for each one.
EU and Great Britain
A CE declaration under the MDR or IVDR is an EU document. Great Britain runs its own system under the UK Medical Devices Regulations 2002, with UKCA marking, UK Approved Bodies and, for manufacturers based outside the UK, a UK Responsible Person. A UKCA-marked device needs its own UK declaration of conformity; the EU declaration does not stand in for it.
GB currently also accepts CE-marked devices under transitional arrangements. According to the MHRA, devices CE marked under the MDR or IVDR can be placed on the GB market until 30 June 2030, and devices under the former MDD or AIMDD until the earlier of certificate expiry or 30 June 2028 (MHRA timelines). In February 2026 the MHRA consulted on recognising CE-marked devices indefinitely (MHRA: implementation of the future regulations). Check the MHRA's current position before building a GB launch plan on either date.
For companies selling in both markets, the risk is not misunderstanding the rules. It is keeping two declarations, two sets of labelling and two sets of registrations in step when the software changes.
Keeping the declaration current
"Continuously update" is one of the shortest obligations in the MDR and one of the most frequently missed. For software, the triggers are wider than most change control procedures assume:
a new software version that falls outside the scope described in the declaration;
a change to the intended purpose or the claims made for the device;
a change of risk class, for example after a new function is added;
a new or reissued notified body certificate;
a change to the manufacturer's legal name, address, SRN or authorised representative;
a new Basic UDI-DI;
a new Union act becoming applicable to the device.
Software teams work in releases and AI teams in model updates. Regulatory documents follow neither rhythm by default. The simplest control is to add one question to every change assessment: does this change affect any field in Annex IV, or the truth of the conformity statement? If the answer is yes, the declaration is updated and re-signed as part of the same change. Our software lifecycle management support covers how to build that link into the release process.
Whether a change also requires notified body involvement is a separate question, answered through the conformity assessment route and the change notification requirements. Updating the declaration doesn't replace that assessment.
A worked example
Hypothetical example: a manufacturer of an AI-enabled triage application that analyses patient-reported symptoms and produces a risk score for clinician review. The software is class IIa under Rule 11 and certified by a notified body.
Its declaration would identify:
the legal manufacturer, its SRN and its registered address;
the Basic UDI-DI and trade name, with the intended purpose matching the instructions for use;
class IIa under Annex VIII, Rule 11;
conformity with the MDR and any other applicable Union act;
the notified body name and number, the conformity assessment procedure followed and the certificate number;
place and date of issue, and the name and function of the signatory.
Six months later the manufacturer adds a new output that changes the clinical claim. Before release, the change assessment asks whether the intended purpose in the declaration still holds, whether the risk class is unchanged and whether the notified body must be informed. Only when those answers are documented is the declaration reissued with the new date.
Conclusion
The declaration is where the work in the technical documentation becomes a legal commitment. Under Article 19, it has to state conformity, contain the Annex IV content, be available in the right languages, combine every applicable Union act into one document and stay up to date. For SaMD and AI-enabled devices, that last requirement is the one that needs a process behind it.
If you are preparing a CE-marked launch, our guide to CE marking a medical device under the MDR shows where the declaration fits in the overall route. For support aligning your declaration with your technical documentation, contact MedQAIR.
Frequently asked questions
What must an EU declaration of conformity contain?
At minimum, the ten items in Annex IV MDR: manufacturer details and SRN, a sole-responsibility statement, the Basic UDI-DI, product identification and intended purpose, risk class, the conformity statement, any common specifications used, notified body and certificate details where applicable, any additional information, and the place, date, signatory and signature.
When is the declaration drawn up?
After conformity has been demonstrated through the applicable conformity assessment procedure (Article 10(6) MDR). For class I devices, that means after the technical documentation in Annexes II and III has been drawn up (Article 52(7)). Where a notified body is involved, its procedure comes first.
How long must the declaration be kept?
At least 10 years after the last device covered by the declaration is placed on the market, and at least 15 years for implantable devices (Article 10(8) MDR).
Does the declaration have to be translated?
Yes. Article 19(1) MDR requires it to be translated into the official Union language or languages required by the Member States where the device is made available.
Is the EU declaration valid in Great Britain?
It supports CE-marked devices placed on the GB market under the MHRA's transitional arrangements. A UKCA-marked device needs a UK declaration of conformity under the UK Medical Devices Regulations 2002. Check the MHRA's current timelines before relying on either route.
Does every software update require a new declaration?
Not automatically. The declaration must be updated when a change affects its content or the truth of the conformity statement, such as a new intended purpose, a change of class, a new certificate or a new Basic UDI-DI. Whether the notified body must be involved is assessed separately.
