---
title: Field Safety Notices Under MDR: How to Communicate with Users and Patients
description: A Field Safety Notice is how you communicate safety corrective actions to users. MDR Article 2(69) defines it, MDCG 2023-3 Rev.2 shapes it. Here is how to write one.
authors: Tibor Zechmeister, Felix Lenhard
category: Post-Market Surveillance & Vigilance
primary_keyword: field safety notices MDR
canonical_url: https://zechmeister-solutions.com/en/blog/field-safety-notices-mdr
source: zechmeister-solutions.com
license: All rights reserved. Content may be cited with attribution and a link to the canonical URL.
---

# Field Safety Notices Under MDR: How to Communicate with Users and Patients

*By Tibor Zechmeister (EU MDR Expert, Notified Body Lead Auditor) and Felix Lenhard.*

> **A Field Safety Notice under MDR is the written communication a manufacturer sends to users or customers in relation to a Field Safety Corrective Action. Article 2(69) of Regulation (EU) 2017/745 defines it as the communication sent by a manufacturer to users or customers in relation to a field safety corrective action. Every FSCA requires one. The FSN explains the problem, the clinical risk, the action the recipient must take, and the timeline, in language the recipient can act on. MDCG 2023-3 Rev.2, revised January 2025, is the interpretive reference for its content and delivery. The FSN is assessed alongside the FSCA itself by the relevant competent authority under Article 89. A compliant FSN that a clinician cannot act on has failed its purpose, no matter how clean it looks on paper.**

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

---

## TL;DR

- A Field Safety Notice is defined in MDR Article 2(69) as the communication sent by a manufacturer to users or customers in relation to a Field Safety Corrective Action. Every FSCA requires an FSN.
- The FSN must identify the affected devices precisely (name, model, lot, serial, UDI range), describe the safety problem in plain language, state the clinical risk, specify the action required of the recipient, set a timeline, and give contact details for follow-up.
- The FSN is addressed to the actual users of the device. Clinicians, patients, procurement officers, biomedical engineers, distributors. Not to a generic mailing list. Who receives it depends on who needs to act.
- MDCG 2023-3 Rev.2 is the authoritative Q&A for FSN content and delivery under MDR. It works alongside Article 87 reporting duties and Article 89 analysis obligations.
- The relevant competent authority reviews the FSN as part of the FSCA assessment under Article 89. The FSN is not an internal document. It is a regulated communication that an authority can require to be rewritten before distribution.

---

## The letter that has to land

There is a moment in every FSCA where a draft letter is sitting on a shared drive and three people are reading it at once. One reads it as a regulatory document. One reads it as a legal document. One reads it as the thing a nurse will glance at on a Tuesday morning between patients. The FSN has to satisfy all three at once, and when it does not, the first two usually win and the third loses. That is the failure mode this post is written against.

MDR Article 2(69) and MDCG 2023-3 Rev.2 together describe what an FSN is and what it has to do. They do not describe how it feels to write one under time pressure with a live FSCA clock running, which is why startups routinely produce FSNs that tick the regulatory boxes and then land in a clinical unit as unreadable noise. The goal of this post is to make the FSN both compliant and usable, because under MDR those are the same requirement read from two different angles.

## What a Field Safety Notice is under Article 2(69)

Article 2(69) of Regulation (EU) 2017/745 defines a field safety notice as the communication sent by a manufacturer to users or customers in relation to a field safety corrective action. Short sentence, heavy implications.

"Communication sent by a manufacturer". The manufacturer is responsible for drafting, issuing, and distributing the FSN. This duty cannot be delegated to a distributor, a contract manufacturer, or a regulatory consultant in a way that removes the manufacturer from the loop. Others may help execute; the manufacturer owns the content and the act of sending.

"To users or customers". The addressees are the people who actually use the device or the entities that hold it in inventory. That set is broader than a marketing contact list. It includes clinicians operating the device, hospitals and clinics as institutional users, pharmacies where relevant, procurement teams, biomedical engineering departments, patients when the device is home-use or patient-facing, and distributors still holding stock.

"In relation to a field safety corrective action". The FSN exists because an FSCA exists. There is no such thing as a standalone FSN. If the manufacturer is sending a safety-relevant letter that is not tied to an FSCA under Article 2(68), it is a different kind of communication (a general safety advisory, an IFU amendment notice, a service bulletin) and the FSN rules do not apply. When an FSCA has been triggered under Article 2(68) and is reportable under Article 87(1)(b), an FSN is required.

The definition is tight, but it carries through to every operational choice: who the letter goes to, how it is worded, how it is delivered, and how it is reviewed. The rest of this post walks each of those choices.

## Required contents of an FSN

MDCG 2023-3 Rev.2 is the interpretive reference for FSN content under MDR. Drawing on the guidance and on standard competent-authority expectations, an FSN should contain, at a minimum:

- **Manufacturer identification**. Legal name, address, single registration number, and a clearly named contact person for the FSCA.
- **Device identification**. Commercial name, model or type, affected lot or serial numbers, UDI range where applicable, and enough detail that a recipient can unambiguously determine whether a device in their inventory is affected.
- **A clear subject line**. "Urgent Field Safety Notice" is the convention. It must not read like marketing. It must not be buried under a product-family headline.
- **The date of issue** and a unique FSN reference number, so that updates to the same FSN can be tracked.
- **A plain-language description of the problem**. What is wrong with the device. Not the root-cause theory, not the engineering hypothesis, but the observable fact that is driving the action.
- **A plain-language description of the clinical risk**. What harm could occur to the patient or user, how likely it is, and in which use scenarios.
- **The action required of the recipient**. Concrete, itemised, actionable. "Stop using affected units until the software update has been applied." "Return affected lots to the distributor for replacement." "Contact the manufacturer to schedule the on-site retrofit."
- **The deadline or timeline** for the required action.
- **Confirmation of receipt and action**. A simple mechanism (reply form, email confirmation, web portal) so the manufacturer can track who has acknowledged and acted on the FSN. Effectiveness tracking is an Article 89 expectation.
- **Contact details** for questions. A named person or team, phone, email, and hours of availability.
- **A statement that the competent authority has been informed**, which is both an Article 87 obligation and a trust signal to the recipient.

The FSN should not contain speculation about root cause beyond what is necessary to make the risk understandable, and it should not contain commercial messaging. The document has one job.

## Who the FSN is addressed to

The FSN goes to whoever has to act. For a hospital-based implantable, that typically means the surgical department, the biomedical engineering team, and the hospital's quality and safety function. Not just the original procurement contact. For a point-of-care device used in primary care, it means the clinicians operating the device and the practice managers who control inventory. For a patient-facing home-use device, it means the patients themselves, usually with a parallel clinician letter.

Where patients are the end users, the FSN has to be written for a non-clinical reader without losing clinical precision. That is harder than it sounds and is the single most common place where compliant FSNs fail to communicate. MDCG 2023-3 Rev.2 addresses the patient-directed FSN case and expects the language to be genuinely accessible, not clinical text with a disclaimer attached.

Distributors and authorised representatives are not the end of the chain. If a distributor receives an FSN, the distributor is expected to forward it downstream to the actual users, and the manufacturer remains responsible for ensuring the FSN reaches the point where the action needs to happen. Cascade distribution is fine; a chain that dead-ends at a distributor's inbox is not.

## Plain language. The test that decides if the FSN works

The plain-language test is the one MDCG 2023-3 Rev.2 keeps coming back to and the one competent authorities actually check. The FSN must be written so that the recipient can read it once and know exactly what to do. If a nurse has to call the manufacturer to ask what the letter means, the FSN has failed in its purpose even if every legal element is present.

Three practical rules carry most of the weight:

- Use the short form of the verb. "Stop using." "Return." "Contact." Not "It is recommended that users consider suspending the operation of the affected devices pending further guidance."
- Put the required action before the explanation. The recipient needs to know what to do in the first ten seconds of reading. The reasoning follows.
- Test the draft on a clinician who is not part of the regulatory team. If that reader cannot, after one read, state the problem, the risk, and the action in their own words, the FSN is not ready to send.

The FSN template should be pre-drafted and pre-tested before any FSCA occurs. Writing the first FSN under live FSCA pressure, from a blank page, is the pattern that produces unreadable letters and late reporting.

## Delivery methods

How the FSN reaches the recipient matters as much as what it says. MDCG 2023-3 Rev.2 does not mandate a single channel, but it does require that the channel is appropriate to the urgency and to the recipient population. In practice, the standard delivery mix includes:

- **Signed letter on manufacturer letterhead**. The document of record, usually in PDF, attached to the other channels.
- **Direct email to named contacts** at institutional users (hospitals, clinics, distributors, home-care providers), from a monitored sender address.
- **Courier or registered mail** where physical delivery is required by the recipient's jurisdiction or where electronic delivery is unreliable.
- **Direct patient communication** where the device is patient-facing, using the channel the patient registered with (post, email, secure portal).
- **Publication on the manufacturer's website**, with a clear link from the main site, so that users outside the primary distribution list can still find the notice.
- **Notification to the competent authorities**, which is separate from the recipient-facing delivery but runs in parallel.

Two delivery rules are non-negotiable. First, delivery has to be traceable. The manufacturer must be able to show who received the FSN and when. Second, the delivery window has to match the urgency of the action: a notice that instructs recipients to stop using a device immediately cannot be delivered on a seven-day mail cycle.

## The regulatory review and approval flow

The FSN is not an internal document. It is reviewed by the relevant competent authority as part of the Article 89 analysis of the FSCA. In the multi-Member-State case, the coordinating competent authority under Article 89(4) takes the lead on the review, so the FSN that ships across the Union is a single aligned version rather than a fragmented set of national letters.

Practically, the flow looks like this. The manufacturer drafts the FSN in parallel with the FSCA decision. The draft FSN is submitted to the relevant competent authority (or the coordinating authority for multi-state cases) together with the FSCA report under Article 87(1)(b). The authority reviews the FSN against MDCG 2023-3 Rev.2 expectations, may require changes to wording, scope, addressees, or timeline, and confirms the version that can be distributed. The manufacturer then distributes the approved FSN through the agreed channels.

Two points that trip startups up. First, the authority's review does not pause the manufacturer's Article 87 reporting obligation. The report goes in without delay, and the FSN review happens alongside, not before. Second, the authority can require changes even after initial distribution has begun, in which case a revised FSN with a new reference number is issued and the distribution is re-run.

## Common mistakes that break FSNs

- **Writing the FSN as a legal document first and a clinical communication second.** The recipient is a clinician, not a lawyer. If the first paragraph reads like a contract, the FSN has already failed.
- **Burying the required action.** The instruction to stop using, return, or contact must be visible in the first screen or page, not on page three under a dense technical explanation.
- **Incomplete device identification.** Affected units that cannot be identified from the FSN are affected units that will not be acted on. UDI ranges, lot numbers, and serial ranges must be exhaustive and correct.
- **Sending the FSN only to the procurement contact.** Procurement contacts are not clinical users. The FSN must reach the people who actually operate the device, even when the procurement contact was the commercial touchpoint.
- **Treating distributors as the endpoint.** The obligation runs through to the user. If the distributor does not forward, the manufacturer has to.
- **Skipping the competent authority review.** The FSN is part of the FSCA file the authority reviews. Distributing the FSN before aligning with the authority can force a retraction and a second, corrected distribution.
- **No receipt confirmation mechanism.** Without confirmation tracking, effectiveness of the FSCA cannot be demonstrated under Article 89, and the authority will not accept closure.
- **Reusing a generic safety-notice template with the device details swapped in.** Templates are useful as a starting point; copied FSNs that were not re-read for the specific device and the specific clinical context read exactly that way, and the recipient can tell.

## The Subtract to Ship angle

The FSN is one of the places where the Subtract to Ship principle shows most clearly. There is a version of this document that runs to fifteen pages of legal cover, internal review trails, and bureaucratic hedging. There is also a version that runs to two pages, is written by someone who has met an actual clinician, and gets the job done. The short version is the one that is both more compliant and more effective, because the FSN is scored on whether the recipient acts, not on how many pages it takes to say so.

The lean FSN system is small. One pre-drafted FSN template reviewed by a clinician and aligned with MDCG 2023-3 Rev.2 content expectations. One named owner for FSN drafting, connected to the FSCA owner named under the Article 87 process. One decision log recording the distribution list and the rationale for who is on it, traceable to Article 2(69). One tracked-delivery mechanism with receipt confirmation. One competent-authority review step built into the FSCA flow. One effectiveness check that closes the loop with Article 89 analysis and feeds back into the PMS plan. Everything traces to a specific MDR article or an MDCG 2023-3 Rev.2 Q. Nothing is there for decoration. For the general methodology behind the lean version, see [the Subtract to Ship framework for MDR](/blog/subtract-to-ship-framework-mdr).

## Reality Check. Where do you stand?

1. Do you have a pre-drafted FSN template, reviewed by a clinician, that can be populated and sent within a single working day of an FSCA decision?
2. Is your FSN template structured so that the required action is visible in the first screen, before the technical explanation?
3. Does your distribution list for each device identify the actual clinical users, not just the procurement contacts?
4. For patient-facing devices, is your patient-directed FSN language tested with a non-clinical reader and genuinely accessible without losing clinical precision?
5. Does your FSN delivery mechanism produce traceable receipt confirmations that can be shown to the competent authority under Article 89?
6. Is your FSN drafting step integrated into the Article 87 reporting flow so that the FSN and the FSCA report are developed in parallel, not sequentially?
7. When was the last time your FSN template was reviewed against the current version of MDCG 2023-3 Rev.2?

## Frequently Asked Questions

**What is a Field Safety Notice under MDR in one sentence?**
A Field Safety Notice is defined in Article 2(69) of Regulation (EU) 2017/745 as the communication sent by a manufacturer to users or customers in relation to a Field Safety Corrective Action. The written notice that explains the problem, the risk, the required action, and the timeline.

**Is the FSN the same as the FSCA?**
No. The FSCA is the corrective action itself (the return, modification, software update, retrofit, withdrawal, or advice on use). The FSN is the written communication that tells users about the FSCA and tells them what to do. Every FSCA requires an FSN, but the FSN is the message, not the action.

**Who signs off on the FSN before it goes out?**
Internally, the FSN is signed by the manufacturer's named responsible person for the FSCA, typically with input from the PRRC under Article 15 and clinical review. Externally, the relevant competent authority reviews the FSN as part of the Article 89 analysis of the FSCA. For devices in more than one Member State, the coordinating competent authority under Article 89(4) takes the lead on that review.

**How quickly does an FSN have to be distributed?**
MDCG 2023-3 Rev.2 expects the FSN to be distributed without undue delay, in a timeframe that matches the urgency of the action. A notice that instructs recipients to stop using a device cannot sit in a mail queue for a week. The delivery window is set by the risk, not by administrative convenience.

**Can an FSN be distributed only by email?**
Email is a valid channel for most professional-user FSNs, provided delivery is traceable and the recipient addresses are current. For home-use or patient-facing devices, the channel has to match the way the patient was registered. The signed letter on manufacturer letterhead is still the document of record in most cases.

## Related reading

- [What Is Vigilance Under MDR?](/blog/what-is-vigilance-mdr) – the pillar post for the vigilance cluster, placing the FSN inside the full reporting framework.
- [MDR Articles 87–92: The Vigilance Reporting Framework](/blog/mdr-articles-87-92-vigilance-framework) – the article-by-article anatomy of the vigilance chapter.
- [Serious Incidents Under MDR](/blog/serious-incidents-mdr) – the Article 2(65) trigger that sits upstream of most FSCAs and FSNs.
- [How to Report a Serious Incident to the Competent Authority](/blog/report-serious-incident-competent-authority) – the reporting workflow that runs alongside FSN drafting.
- [Vigilance Reporting Timelines: 15-Day, 10-Day, and 2-Day Clocks](/blog/vigilance-reporting-timelines-15-day-2-day) – the Article 87(3) clocks that set the pace for FSN distribution.
- [Trend Reporting Under MDR Article 88](/blog/trend-reporting-mdr-article-88) – how trend signals can escalate into an FSCA and FSN.
- [Field Safety Corrective Actions (FSCAs) Under MDR: When and How to Act](/blog/field-safety-corrective-actions-fscas-mdr) – the FSCA that every FSN is attached to.
- [MDCG 2023-3 Rev.2 Explained](/blog/mdcg-2023-3-explained) – the interpretive reference for FSN content and delivery.
- [The Subtract to Ship Framework for MDR](/blog/subtract-to-ship-framework-mdr) – the methodology behind the lean FSN process in this post.

## Sources

1. Regulation (EU) 2017/745 of the European Parliament and of the Council of 5 April 2017 on medical devices, Article 2(69) (definition of field safety notice), Article 87 (reporting of serious incidents and field safety corrective actions), Article 89 (analysis of serious incidents and field safety corrective actions). Official Journal L 117, 5.5.2017.
2. MDCG 2023-3 Rev.2. Questions and Answers on vigilance terms and concepts as outlined in Regulation (EU) 2017/745 and Regulation (EU) 2017/746, first publication February 2023, Revision 2 January 2025.
3. EN ISO 13485:2016 + A11:2021. Medical devices. Quality management systems. Requirements for regulatory purposes.
4. EN ISO 14971:2019 + A11:2021. Medical devices. Application of risk management to medical devices.

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*This post is part of the Post-Market Surveillance & Vigilance series in the Subtract to Ship: MDR blog. Authored by Felix Lenhard and Tibor Zechmeister. The FSN is the one page of the entire vigilance system that a clinician actually reads. Everything else is upstream plumbing; the FSN is where the safety message lands. Write it for the person who has to act, and the rest of the system starts to make sense.*

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*This post is part of the [Post-Market Surveillance & Vigilance](https://zechmeister-solutions.com/en/blog/category/pms-vigilance) cluster in the [Subtract to Ship: MDR Blog](https://zechmeister-solutions.com/en/blog). For EU MDR certification consulting, see [zechmeister-solutions.com](https://zechmeister-solutions.com).*