When a Notified Body classifies your device into a higher class than you believe applies, you have the right to argue the case. And, where the disagreement cannot be resolved between you, Article 51(2) of Regulation (EU) 2017/745 provides a route for the competent authority to decide. Winning a classification dispute is not about rhetoric. It is about producing a written classification argument grounded in the actual Annex VIII rule, the intended purpose under Article 2(12), and the relevant MDCG guidance, then presenting it in a way that gives the Notified Body reviewer room to agree with you rather than back down.

By Tibor Zechmeister and Felix Lenhard. Last updated 10 April 2026.

TL;DR

  • Classification under the MDR is the manufacturer's responsibility, but the Notified Body reviews it during conformity assessment and can dispute it. A dispute does not automatically mean the Notified Body is right.
  • Article 51(2) of Regulation (EU) 2017/745 provides the formal mechanism for resolving classification disagreements. Where the manufacturer and the Notified Body cannot agree, the matter is referred to the competent authority of the Member State where the manufacturer has its registered place of business.
  • Winning a defensible position requires a written classification argument citing the specific Annex VIII rule, the intended purpose per Article 2(12), and MDCG 2021-24 (October 2021) where applicable.
  • Escalation to a competent authority referral under Article 51(2) is a real option, not a bluff. It is also slow, public, and reputationally visible. Most disputes are better resolved one level earlier, in the written exchange with the Notified Body reviewer.
  • The most common outcome of a well-prepared classification dispute is neither a full win nor a full loss. It is a negotiated position where the manufacturer wins on the specific question that matters most and concedes on a point that does not.

How classification disputes actually arise

A classification dispute almost never starts as a dispute. It starts as a note on a Notified Body review letter. The reviewer reads the technical documentation, looks at the classification section, and writes something like "The manufacturer has classified the device as Class IIa under Annex VIII Rule 10. The reviewer considers Rule 11 to apply, producing Class IIb. Please clarify." That one sentence is the opening of a dispute.

The origin is usually one of three things. The reviewer reads the intended purpose differently than the manufacturer intended it. The reviewer applies a rule the manufacturer did not consider. Or the reviewer is applying MDCG 2021-24 or internal Notified Body guidance that the manufacturer has not mapped to. None of these mean the manufacturer is wrong. They mean two people have read the same Regulation and the same device file and arrived at different classifications.

What makes classification disputes difficult is the asymmetry. The Notified Body reviewer is paid to find issues, and their decisions carry weight with their colleagues, their certification committee, and, ultimately, the market. A manufacturer pushing back looks, on the face of it, like a manufacturer trying to avoid work. That perception is the first thing a good dispute strategy has to neutralise. The defence is not "we don't want to do the extra work." The defence is "here is the specific rule, here is the specific intended purpose, and here is why the rule produces this class."

Building an evidence-based argument

A classification argument that wins a dispute has four components, and they are not interchangeable. Skip one and the argument falls apart.

The intended purpose in a single paragraph. Article 2(12) of Regulation (EU) 2017/745 defines intended purpose as "the use for which a device is intended according to the data supplied by the manufacturer on the label, in the instructions for use or in promotional or sales materials or statements and as specified by the manufacturer in the clinical evaluation" (Regulation (EU) 2017/745, Article 2, point 12). The paragraph must be internally consistent with the label, the IFU, the website, and the clinical evaluation. If the reviewer finds a divergence, your argument is dead before it starts.

The specific Annex VIII rule, cited by number and paragraph. Not "Rule 10" but "Annex VIII, Section 3, Rule 10, second indent." Not "the rule for active devices" but the specific sub-rule. The Annex VIII text is the authority. Paraphrases will not carry you through a dispute.

The mapping of intended purpose to rule. This is the interpretive step. Walk through how each element of the rule maps to the intended purpose. If the rule says "active therapeutic device," show why your device is active under the Annex VIII Section 1 definition, why it is therapeutic under the definition, and where in the intended purpose that is established. If the rule has an escalation trigger, show explicitly why the trigger does not apply. Do not leave that to inference.

The cross-check against MDCG 2021-24 and, where relevant, the Borderline Manual. MDCG 2021-24 (Guidance on classification of medical devices, October 2021) is the authoritative interpretation guide for Annex VIII. If the guidance supports your position, cite it. If the guidance is silent, say so explicitly. If the guidance appears to contradict you, address it head-on rather than hoping the reviewer will not notice. Reviewers always notice.

The whole argument sits in a document of two to five pages, depending on the complexity of the device. Long enough to be complete, short enough for a busy reviewer to read in one sitting, formatted so every claim is traceable to a citation.

Tibor's hardware-software classification defence

A combined hardware-software device. The software side was clearly Class IIa. No dispute, software providing information used for clinical decisions, straight application of Rule 11. The hardware side was where the disagreement lived. The question was whether the hardware was plain Class I or Class I with measurement function. The Notified Body reviewer initially assumed measurement function applied. The distinction mattered because the Im sub-class triggers additional conformity assessment obligations for the metrological aspects. More cost, more time, a different certification route on the hardware side.

The defence was not a rhetorical push-back. It was a careful written argument. The team went through the Annex VIII Section 1 definition of measurement function, then through what the hardware actually did, what quantitative output it produced, how that output was used downstream, and whether the intended purpose referred to measurement at all. The intended purpose did not. The quantitative output was consumed by the software, which was already Class IIa and handled the clinically meaningful interpretation. The hardware on its own produced a raw signal, not a measurement in the Annex VIII sense.

The reviewer read the argument, matched it against Annex VIII and the internal Notified Body guidance, and accepted the Class I position without measurement function. The hardware stayed at Class I. The software stayed at Class IIa. The conformity assessment route on the hardware side shrank accordingly.

The lesson is not that every classification dispute can be won. The lesson is that where the rules allow judgment. And they often do. A rigorous written argument backed by the actual Annex VIII text and a precise reading of the intended purpose produces outcomes. The team did not win by pushing. They won by reading the Regulation more carefully than the reviewer expected.

Article 51(2). The competent authority referral

Where the manufacturer and the Notified Body cannot agree, the MDR provides a formal mechanism. Article 51(2) of Regulation (EU) 2017/745 states that any dispute between the manufacturer and the Notified Body concerned arising from the application of Annex VIII shall be referred for a decision to the competent authority of the Member State in which the manufacturer has its registered place of business. Where the manufacturer has no registered place of business in the Union, the matter is referred to the competent authority of the Member State in which the authorised representative has its registered place of business.

Two things are worth understanding about this route before invoking it.

First, it is real. It is not a theoretical mechanism that no one uses. Competent authorities receive referrals, and they produce decisions. A manufacturer with a solid Annex VIII argument and a stubborn Notified Body reviewer has a genuine path to an external decision.

Second, it is slow and visible. The referral involves submitting the classification argument to a national regulator, waiting for their review, and accepting their decision. The timeline is weeks to months, not days. The decision is visible to the Notified Body, to the competent authority, and, depending on the Member State, potentially to the Commission and other authorities. A manufacturer who loses a referral may have damaged their standing with both the Notified Body and the authority. A manufacturer who wins has a decision that is hard for anyone to overturn but has also spent significant time and political capital to get it.

The practical implication is that Article 51(2) is a real backstop, not a first move. The first move is a written argument. The second move is a meeting with the reviewer and their technical colleague. The third move, if the argument is strong and the dispute is important, is escalation within the Notified Body. Asking for a second reviewer or the certification committee to look at the file. Article 51(2) is the fourth move, used when everything earlier has failed and the classification genuinely matters.

When to escalate and when to concede

Not every classification dispute is worth fighting. A good framework for the decision has three questions.

Does the dispute actually change the project economics? A dispute between Class IIa with one rule citation and Class IIa with a different rule citation is a clerical dispute. Concede it, fix the citation, move on. A dispute between Class IIa and Class IIb changes the depth of the Notified Body assessment and the technical documentation burden. Worth fighting. A dispute between Class IIb and Class III changes whether clinical investigations are mandatory. Very much worth fighting.

Is the argument defensible against MDCG 2021-24 and the actual Annex VIII text? If your position is supported by a clear reading of the rule and the guidance is either neutral or in your favour, you have a defensible position worth escalating. If your position requires a creative reading of a rule that MDCG 2021-24 explicitly addresses against you, you do not. Concede early. Fighting a lost argument costs credibility you will need for the next dispute.

Can you afford the time? A Notified Body dispute adds weeks to the review cycle. A competent authority referral adds months. For a startup with a runway measured in months, the question is not just whether you can win but whether you can afford to win. Sometimes the right move is to accept the higher class, get certified on the original timeline, and plan a post-certification reclassification once the product is on the market and generating revenue.

The decision is not moral. It is strategic. A manufacturer who fights every dispute on principle loses more than they win. A manufacturer who concedes every dispute to avoid friction overpays for certification and carries the wrong class forward into every downstream decision. The discipline is to pick the disputes where the stakes are real, the argument is defensible, and the timeline can absorb the delay.

Common outcomes

Classification disputes, in Tibor's experience, resolve in roughly three patterns.

Full win at the written-argument stage. The manufacturer produces a careful written argument citing the specific Annex VIII rule, the intended purpose, and MDCG 2021-24. The reviewer reads it, checks it against their own sources, and accepts the position. No escalation. No referral. The outcome of the hardware-software dispute above was this kind of win.

Partial win after discussion. The manufacturer and the reviewer meet, walk through the rule together, and land on a position that neither started with. Perhaps the classification stays at the higher class but the conformity assessment route uses a lighter annex. Perhaps the class drops but the clinical evidence expectations stay at the higher-class level. Partial wins are the most common outcome when both sides are acting in good faith.

Full loss, followed by acceptance or referral. The manufacturer's argument fails. The reviewer confirms the higher class. At this point, the manufacturer either accepts and replans the project, or escalates to Article 51(2) if the stakes justify it. The second path is rare and slow, but it is available when the dispute is genuinely important.

A pattern worth noting: manufacturers who invest in a good classification argument up front. Before the Notified Body even sees the file. Rarely end up in disputes at all. The investment pays for itself in the form of disputes that do not happen.

The Subtract to Ship angle

The Subtract to Ship framework for MDR compliance treats classification as the second of four passes, and the discipline of the pass is to find the lowest defensible classification. Not the lowest wishful classification, and not the highest cautious classification. Classification disputes are the moment that discipline is tested.

A Subtract to Ship classification is already written as if it will be disputed. The intended purpose is on one page. The rule citation is specific. The mapping from rule to intended purpose is explicit. The MDCG 2021-24 cross-check is in the file. When the Notified Body reviewer challenges it, the response is not a scramble. It is the existing classification document, possibly with a paragraph added to address the specific challenge. The manufacturer who has done the Subtract to Ship classification pass properly has already written most of the dispute defence before the dispute exists.

The same discipline tells you when to concede. If a challenge exposes that the original classification was not actually defensible. That the rule citation was vague, or the intended purpose was inconsistent with the IFU, or MDCG 2021-24 clearly disagrees. Then conceding is not a loss. It is the correct output of the framework. Subtract to Ship is about defending what is defensible, not defending what is convenient.

Reality Check. Are you ready for a classification dispute?

  1. Do you have a written classification argument for your device, two to five pages, citing the specific Annex VIII rule and the intended purpose under Article 2(12)?
  2. If the Notified Body reviewer challenged your classification tomorrow, could you respond within a week with a complete written defence rather than a scramble?
  3. Have you cross-checked your classification against MDCG 2021-24 (October 2021) and documented the cross-check in the file?
  4. Have you mapped every element of the applicable rule. Not just "Rule 10" but each sub-clause. To the intended purpose explicitly?
  5. Do you know which classification disputes on your device would change the project economics and which would only change the citation format?
  6. Have you thought through the Article 51(2) escalation route, and do you know which competent authority would receive a referral?
  7. Is your intended purpose consistent across the label, the IFU, the website, and the clinical evaluation, so that a reviewer cannot open the dispute by pointing at an inconsistency?

Frequently Asked Questions

What happens if I disagree with my Notified Body's classification of my device? You can argue the case in writing, citing the specific Annex VIII rule and the intended purpose under Article 2(12) of Regulation (EU) 2017/745. Most disputes resolve at this stage when the manufacturer produces a careful, sourced argument. Where agreement cannot be reached, Article 51(2) of the MDR provides a formal route: the dispute is referred to the competent authority of the Member State in which the manufacturer has its registered place of business.

Is the Notified Body always right about classification? No. Classification under the MDR is the manufacturer's responsibility in the first instance, and the Notified Body reviews rather than authors it. Reviewers can and do disagree on classification, and a well-prepared written argument from the manufacturer can change the outcome. The question is not who has the authority but which reading of Annex VIII is actually correct against the specific intended purpose.

How does Article 51(2) of the MDR work in practice? Article 51(2) states that disputes between the manufacturer and the Notified Body arising from the application of Annex VIII are referred to the competent authority of the Member State in which the manufacturer has its registered place of business. The competent authority reviews the arguments from both sides and issues a decision. The process takes weeks to months and should be treated as a backstop, not a first move.

Can I change my Notified Body to avoid a classification dispute? Changing Notified Bodies mid-project is possible but rarely a solution to a classification dispute. A second Notified Body reading the same intended purpose and the same Annex VIII will usually reach similar conclusions, and the transition cost is significant. A better move is to fix the classification argument first, then assess whether the Notified Body relationship is actually the problem or whether the classification file was the problem all along.

How do I know when to concede a classification dispute rather than fight it? Concede when the dispute does not change project economics, when your argument is not supported by Annex VIII or MDCG 2021-24, or when the timeline cost of fighting exceeds the business value of winning. Fight when the dispute changes the conformity assessment route, when the argument is defensible against the actual Regulation text, and when the project can absorb the delay. The decision is strategic, not moral.

Sources

  1. Regulation (EU) 2017/745 of the European Parliament and of the Council of 5 April 2017 on medical devices, Article 2, point 12 (definition of intended purpose), Article 51 (classification) including Article 51(2) (referral to competent authority), Article 52 (conformity assessment procedures), Annex VIII (classification rules). Official Journal L 117, 5.5.2017.
  2. MDCG 2021-24. Guidance on classification of medical devices, October 2021.

This post is part of the Device Classification & Conformity Assessment series in the Subtract to Ship: MDR blog. Authored by Felix Lenhard and Tibor Zechmeister. Classification disputes are one of the moments where the investment in a careful, written classification argument pays back many times over. And where an experienced sparring partner who has sat on both sides of the Notified Body table can be the difference between a dispute that resolves in a week and a dispute that drags the project off its timeline.