Substantial modification: when to re-certify in the EU

Hugues Orgitelloupdated 7 Oct 202621 min read

A product placed on the EU market with a valid CE marking can still be repaired, upgraded, refurbished and updated, by its manufacturer or by someone else. What decides the consequences is whether the change is a "substantial modification". If it is, section 2.1 of the Blue Guide says the product must be considered as a new product, and the person who made the change has to fulfil the same requirements as an original manufacturer. Until recently this rested on guidance alone. Since 13 December 2024 the GPSR defines the term in law, the Machinery Regulation does so from 20 January 2027, and the Cyber Resilience Act does so from 11 December 2027, each with a slightly different wording. This guide sets the texts side by side, shows where they differ, and lists the readings they contradict.

Why the concept exists

EU product law attaches conformity obligations to the moment a product is placed on the market or put into service, and the Blue Guide states that the product must comply with the legal requirements in place at that time. Without a rule on later changes, a product could be deeply altered after that moment and still carry a CE marking issued for a design that no longer exists.

The Blue Guide closes the gap in its subsection "Repairs and modifications to products": some life extension processes maintain or restore the product, others "imply that substantial modifications are made to the product". The second kind turns the product into a new one, and the conformity question is asked again against its new state.

This matters well beyond the original factory. Importers, distributors, repairers, refurbishing companies and integrators can all make changes, and the texts say when each of them becomes a manufacturer.

The Blue Guide test

The Blue Guide (OJ C 247, 29.6.2022, section 2.1) says a product that has been subject to important changes or overhaul must be considered as a new product if all three conditions are met:

1. Its original performance, purpose or type is modified, without this being foreseen in the initial risk assessment
2. The nature of the hazard has changed or the level of risk has increased in relation to the relevant Union harmonisation legislation
3. The product is made available (or put into service if the applicable legislation also covers putting into service)

This has to be assessed case by case, in view of the objective of the legislation and the type of products it covers. The same section adds four points that are often missed:

• Rebranding is enough on its own. "In any case, a modified product sold under the name or trademark of a natural or legal person different from the original manufacturer, should be considered as new."
• The modifier decides and proves. The person who carries out important changes is responsible for verifying whether the product is new. If it is, that person becomes the manufacturer and the new manufacturer name and contact address must be indicated on the product.
• Only the affected aspects are re-tested. The technical documentation is updated "in as much as the modification has an impact"; it is not necessary to repeat tests on aspects not impacted, but the modifier must demonstrate that, and still draws up a declaration of conformity in its own name.
• Software follows the same test. A software update is a substantial modification where it modifies the original intended functions, type or performance in a way not foreseen in the initial risk assessment, the hazard or risk level changes because of it, and the product is made available.

How each text defines it

The Blue Guide is guidance. Several regulations now carry a definition of their own, and they are not identical. This table puts the operative provisions side by side.

Text	Provision	Applies from	What makes a modification substantial	Who becomes manufacturer	Exclusions and limits
Blue Guide 2022	Section 2.1	Guidance, published 29 June 2022	Performance, purpose or type modified and not foreseen in the risk assessment, and hazard changed or risk increased, and product made available	The person carrying out the substantial modification	Repairs with identical or similar parts; better-performing spare parts within the originally conceived envelope
Regulation 2023/988 (GPSR)	Article 13(2) and 13(3)	13 December 2024	Physical or digital modification with an impact on safety, not foreseen in the initial risk assessment, and nature of hazard changed, new hazard created or risk increased	Any person other than the manufacturer who substantially modifies the product	Not where made by consumers themselves or on their behalf for their own use (13(3)(c)); obligations cover the affected part, or the whole product if safety as a whole is impacted
Regulation 2023/1230 (machinery)	Article 3(16), Article 18	20 January 2027	Physical or digital modification, not foreseen or planned by the manufacturer, affecting safety by creating a new hazard or increasing a risk, which requires either guards or protective devices whose processing needs a change to the existing safety control system, or additional protective measures for stability or mechanical strength	Any person carrying out the substantial modification (Article 18); importers and distributors also when they modify a product so that compliance might be affected (Article 17)	A non-professional user modifying their own machinery for their own use; obligations limited to the affected machine when it is part of an assembly, as shown in the risk assessment
Regulation 2024/2847 (CRA)	Article 3(30), Articles 21 and 22	11 December 2027	A change after placing on the market that affects compliance with the essential cybersecurity requirements of Annex I Part I or changes the intended purpose for which the product was assessed	Importers and distributors (Article 21); any other person who carries it out and makes the product available (Article 22)	Obligations limited to the affected part unless cybersecurity of the whole product is impacted (Article 22(2))
Directive 2014/53/EU (RED)	Article 14; RED Guide section 1.5	In force; RED Guide July 2026 version	Blue Guide test, with the radio interface added to the list of what a software update may modify	Importers and distributors who modify equipment so that compliance may be affected (Article 14)	Repairs and software updates assimilated to maintenance when compliance is not affected
Regulation 2017/745 (MDR)	Article 16(1)(b) and (c); Article 2(31)	26 May 2021	Changing the intended purpose, or modifying a device so that compliance may be affected; fully refurbishing a device	Distributor, importer or other person (Article 16); whoever fully refurbishes and markets under its name (Article 2(30))	Translation of information and some repackaging (Article 16(2)); assembling or adapting a device for an individual patient without changing its intended purpose

Two differences carry practical weight. The CRA definition has two alternative limbs and no risk-increase condition: a change that affects compliance with the cybersecurity requirements is enough. The machinery definition is the narrowest: a new hazard or increased risk is substantial only when it calls for new guards or protective devices that need a change to the safety control system, or for new stability or strength measures.

Key dates

Date	Event	Source
26 May 2021	MDR applies; legacy devices must not undergo significant changes in design or intended purpose after this date to keep the transition	MDR Article 120; MDCG 2020-3 Rev.1 section 4.1
29 June 2022	Blue Guide 2022 published, with the software paragraph in section 2.1	OJ C 247
13 December 2024	GPSR applies, with the first statutory definition of substantial modification for consumer products	Regulation 2023/988, Article 52
1 August 2025	RED Article 3(3)(d), (e) and (f) apply to the categories set by Delegated Regulation (EU) 2022/30	Decision (EU) 2025/138 cites EN 18031-1/-2/-3
11 September 2026	CRA Article 14 reporting obligations apply, including to products placed on the market before 11 December 2027	CRA Articles 69(3) and 71(2)
20 January 2027	Machinery Regulation applies and Directive 2006/42/EC is repealed (dates corrected by corrigendum OJ L 169, 4.7.2023)	Regulation 2023/1230
11 December 2027	CRA applies in full; products placed on the market before that date fall under it only if they are substantially modified from that date	CRA Article 69(2)
31 December 2027 / 31 December 2028	End of the MDR legacy transition, by device class, provided there is no significant change in design or intended purpose	MDR Article 120(3) and (3c) as amended by Regulation 2023/607

What is not a substantial modification

The Blue Guide says repaired products that are not considered new "do not need to undergo conformity assessment again", whether the product was placed on the market before or after the legislation entered into force, and even if it was temporarily exported for repair. Maintenance operations are "basically excluded" from Union harmonisation legislation.

Activity	New product?	Text
Repair after a defect, with an identical part	No	Blue Guide 2.1
Repair with a similar part (technical progress, discontinued original)	No	Blue Guide 2.1
Spare part that performs better, product still within the originally conceived use and performance range	No	Blue Guide 2.1
Software update or repair that does not affect compliance	No	Blue Guide 2.1; RED Guide 1.5
Security update designed to decrease cybersecurity risk, intended purpose unchanged	No	CRA recital 39
Minor functionality update (visual enhancement, new pictograms or languages)	Generally no	CRA recital 39
Translation of the information supplied, or necessary repackaging of a medical device	Not a modification under MDR Article 16(1)(c)	MDR Article 16(2)
Feature update that modifies intended functions, type or performance and increases risk	Yes	Blue Guide 2.1; CRA recital 39
Change of intended purpose	Yes under CRA and MDR; under the Blue Guide when risk also changes	CRA Article 3(30); MDR Article 16(1)(b)
Product resold under another name or trademark after modification	Yes	Blue Guide 2.1

Repair and equivalent parts

The Blue Guide describes repair as replacing a defective or worn item by a spare part "either identical, or at least similar, to the original part", or exchanging cards, components or sub-assemblies. A better spare part does not make the product new as long as the product stays within "the intended use, range of performance and maintenance originally conceived at the design stage". Outside that envelope, the three conditions apply. A substitute with a different radio front end, a higher power rating or a different switching frequency can change EMC or radio behaviour, which is why the original design envelope has to be documented. The detailed rules on swapping parts are covered in component substitution rules.

Refurbished and reconditioned products

The Blue Guide applies Union harmonisation legislation to new products and to used and second-hand products imported from a third country when they enter the Union market for the first time. For products already on the Union market, refurbishment is assessed with the same test as any other change.

• Restoring a unit by cleaning, testing and replacing worn parts with identical or similar ones is repair or maintenance.
• Upgrading a unit so that its function, type or performance changes and the risk increases makes it a new product, and the refurbisher becomes the manufacturer.
• Rebranding: a refurbished unit sold under the refurbisher name or trademark is new under the Blue Guide whatever the depth of the work.

CRA recital 42 refers to the definitions of refurbishment, maintenance and repair in Article 2, points (18), (19) and (20), of the Ecodesign Regulation 2024/1781 and says these "do not necessarily" lead to a substantial modification, for instance if the intended purpose and functionalities are not changed and the risk is unaffected. For medical devices, MDR Article 2(31) defines "fully refurbishing" as the complete rebuilding of a device already placed on the market, or the making of a new device from used devices, combined with a new lifetime, and Article 2(30) makes the person who does it and markets the device under its name its manufacturer. The obligations of each economic operator along the chain are set out in authorised representative and importer obligations.

Software and firmware updates

The Blue Guide says the initial risk assessment must foresee the risks of software integrated in the product, including "the safety-related aspects of cyber risks and risks related to the loss of connectivity of devices". Updates are then tested against the three conditions. Each regime adds its own detail.

Radio equipment (RED)

Section 1.5 of the RED Guide (July 2026 version) repeats the Blue Guide software test and adds "radio interface" to the list: a software update is a substantial modification where it modifies the original intended functions, radio interface, type or performance in a way not foreseen in the initial risk assessment, the hazard or risk changes, and the product is made available. Article 14 of Directive 2014/53/EU makes an importer or distributor who modifies radio equipment already on the market "in such a way that compliance with this Directive may be affected" subject to the manufacturer obligations of Article 10.

Since 1 August 2025, Article 3(3)(d), (e) and (f) (network protection, personal data and privacy, protection from fraud) apply to the categories of radio equipment set by Delegated Regulation (EU) 2022/30. For that equipment, an update that weakens one of these properties touches an essential requirement, and the three conditions decide whether it makes the product new.

Products with digital elements (CRA)

From 11 December 2027, the Cyber Resilience Act uses its own definition (Article 3(30)): a change after placing on the market that affects compliance with the essential cybersecurity requirements of Annex I Part I, or that changes the intended purpose for which the product was assessed. Recital 39 gives the reading:

• A security update designed to decrease the level of cybersecurity risk, without modifying the intended purpose, is not a substantial modification, even when it modifies functions or performance for that sole purpose.
• A minor functionality update, such as a visual enhancement or new pictograms or languages, should not generally be one.
• A feature update that modifies the original intended functions, type or performance and meets the criteria is one, because new features "typically" broaden the attack surface. The recital gives the example of a new input element that requires input validation.
• Bundling a feature update with a security update does not change the answer.

Recital 40 adds that a manufacturer who has placed a substantially modified version of a software product on the market may provide security updates for the support period only for the last version placed on the market, if users of earlier versions have free access to it without extra hardware or software costs. Article 69(2) is the transition rule: a product placed on the market before 11 December 2027 is subject to the CRA requirements only if it is substantially modified from that date, but Article 14 reporting applies to all such products from 11 September 2026 (Article 69(3)). Article 26(2)(d) requires the Commission guidance on the CRA to address the concept of substantial modification. See the Cyber Resilience Act guide.

Machinery Regulation 2023/1230

Regulation 2023/1230 applies from 20 January 2027, when Directive 2006/42/EC is repealed, so machinery placed on the market today is still assessed under the Directive. Its definition (Article 3(16)) covers modifications "by physical or digital means", so a software change is in scope, but only if it was not foreseen or planned by the manufacturer, affects safety by creating a new hazard or increasing an existing risk, and requires new guards or protective devices whose processing needs a change to the existing safety control system, or new protective measures for stability or mechanical strength. A software change to a safety function that creates no such need is not a substantial modification under this definition. Article 18 makes the person who carries out a substantial modification the manufacturer, obliged to apply the conformity assessment procedure of Article 25(2), (3) and (4), and exempts a non-professional user who modifies their own machinery for their own use. More on the transition in Machinery Directive 2006/42 and Regulation 2023/1230.

Medical devices

Regulation 2017/745 (MDR) uses two separate mechanisms, and they are often confused.

• Changes to a device certified under the MDR. Annex IX section 4.10 says changes to the approved device require approval from the Notified Body that issued the EU technical documentation assessment certificate where they could affect the safety and performance of the device or the conditions prescribed for its use. The Notified Body decides whether a new conformity assessment under Article 52 is needed or whether a supplement to the certificate is enough.
• Legacy devices still covered by a Directive certificate. Article 120(3c)(b), as amended by Regulation 2023/607, allows them on the market until 31 December 2027 or 31 December 2028 only if there are "no significant changes in the design and intended purpose". MDCG 2020-3 Rev.1 (May 2023) explains that a significant change has two cumulative elements (a change in design or intended purpose, and significance), that administrative changes and changes to the manufacturing process are generally outside it, and that a device with a significant change can only be placed on the market under the MDR.

Separately, Article 16(1) makes a distributor, importer or other person who changes the intended purpose of a device, or modifies it so that compliance may be affected, assume the obligations of a manufacturer. See the MDR guide.

Consequences when a modification is substantial

Once a change is substantial, the product is treated as new and the obligations of a manufacturer apply to whoever made it.

• Conformity assessment. The procedure laid down by the applicable legislation is applied again. The Blue Guide calls it "a full conformity assessment", while accepting that tests are not repeated for aspects not impacted by the modification, which the modifier must demonstrate.
• Technical documentation. Updated in as much as the modification has an impact on the requirements. See technical documentation file contents.
• Declaration of conformity. The modifier draws up a declaration of conformity on its sole responsibility, even when it relies on existing tests.
• Marking and identification. The CE marking is affixed, with the Notified Body number where one was involved in production control, and the new manufacturer name and contact address appear on the product.
• Ongoing obligations. Traceability, cooperation with market surveillance authorities under Regulation 2019/1020, and the vulnerability handling and reporting duties of the CRA for products with digital elements.

Who becomes the manufacturer

Who modifies	Status after a substantial modification	Text
Original manufacturer	Remains manufacturer; the modified product is assessed as a new product	Blue Guide 2.1
Importer or distributor	Manufacturer (RED and Machinery: already when compliance may or might be affected)	RED Article 14; Machinery Article 17; CRA Article 21; MDR Article 16
Refurbisher, repairer, integrator	Manufacturer if the work is a substantial modification or the product is sold under its name	Blue Guide 2.1; GPSR Article 13(2); CRA Article 22; Machinery Article 18
Professional user modifying machinery for its own use	Manufacturer under the Machinery Regulation, which covers putting into service	Machinery Article 18
Consumer or non-professional user, own use	Not a manufacturer	GPSR Article 13(3)(c); Machinery Article 18, third paragraph; Blue Guide 2.1 (end users are not economic operators)

The Blue Guide adds that occasional supplies by hobbyists should not in principle be considered a commercial activity, so a private sale of a modified item is not, on its own, making available on the market. Enforcement and recalls of non-compliant modified products are covered in market surveillance and Safety Gate.

A decision path

Walk these questions in order for any planned change.

Question 1: Which texts apply to the product?

List every act: GPSR for consumer products, RED, LVD and EMC, Machinery, CRA from 11 December 2027, MDR. Their definitions differ (see the table above), so the answer can be "substantial" under one and not under another.

Question 2: Is it repair, maintenance or a non-affecting update?

Identical or similar spare parts, better parts within the originally conceived envelope, and updates that do not affect compliance are outside the concept. Document the reasoning and stop here.

Question 3: Will it be sold under another name or trademark?

If yes, the Blue Guide treats the modified product as new whatever the depth of the change.

Question 4: Does it change performance, purpose, type or (for radio) the radio interface, unforeseen in the risk assessment?

If no, it is not substantial under the Blue Guide test. Under the CRA, still check whether it affects compliance with an Annex I Part I requirement.

Question 5: Has the hazard changed or the risk increased?

All Blue Guide conditions must be met. Under the Machinery Regulation, also check whether the risk calls for new guards or protective devices that change the safety control system, or new stability or strength measures.

Question 6: If substantial, what has to be redone?

Apply the conformity assessment procedure of the applicable legislation, re-test the affected aspects, document why the rest is unaffected, update the technical documentation, draw up a new declaration of conformity, mark the product with the new manufacturer details, and inform any Notified Body that holds a certificate for the product.

The US contrast: FCC permissive changes

The United States handles changes to certified equipment through 47 CFR 2.1043, which creates filing classes under the same FCC ID.

FCC change class	Meaning (47 CFR 2.1043)	Filing
Class I	Modifications that do not degrade the characteristics reported and accepted at certification	No filing
Class II	Modifications that degrade the performance characteristics reported at certification, still meeting the minimum requirements	Filing with test results of the affected characteristics; not marketed before acknowledgement
Class III	Software changes to a software defined radio that change frequency range, modulation type or maximum output power outside the approved parameters, or the circumstances of operation	Filing with description and test results; only for equipment with no Class II change
New grant	Changes to the basic frequency determining and stabilising circuitry, frequency multiplication stages, basic modulator circuit or maximum power or field strength ratings (outside Class III)	New application for certification

Class I and Class II changes may only be made by the grant holder, except as specified. Software changes that do not affect RF emissions need no filing and may be made by parties other than the grantee. The detail is covered in change management under FCC Class II permissive changes.

The EU has no filing classes and no central product identifier under the CE system, so deciding whether a change is substantial falls on the economic operator, with market surveillance as the backstop. But the EU outcome is not all-or-nothing either: the Blue Guide, the GPSR, the CRA and the Machinery Regulation all limit re-assessment to what the modification affects. For the broader picture, see the CE pillar.

Claims the texts contradict

Common claim	What the text says
"A substantially modified product can be regarded as new."	The Blue Guide says it "must be considered as a new product" when the three conditions are met.
"A change of performance, purpose or type makes the product new."	Not alone: under the Blue Guide the hazard must also have changed or the risk increased, and the product must be made available. Rebranding is the exception that needs no risk test.
"EU law is binary: if substantial, everything is re-assessed."	The Blue Guide says tests are not repeated for aspects not impacted; GPSR Article 13(2), CRA Article 22(2) and Machinery Article 18 limit the obligations to the affected part when the whole is not impacted.
"Under the Machinery Regulation any software change to a safety function is a candidate for substantial modification."	Article 3(16) also requires that the new hazard or increased risk need new guards or protective devices changing the safety control system, or new stability or strength measures.
"Any update that weakens a cybersecurity property is substantial under RED Article 3(3)."	The RED Guide applies the Blue Guide three conditions. The CRA, from 11 December 2027, is the text where affecting a cybersecurity requirement is enough on its own.
"Products placed on the market before 11 December 2027 are outside the CRA."	Article 69(2): they fall under it if substantially modified from that date, and Article 14 reporting applies to them from 11 September 2026.
"Under the MDR, a significant change requires the Notified Body."	"Significant change" is the Article 120 test for legacy devices; such a change ends the legacy route and the device must go through the MDR. For MDR-certified devices, Annex IX section 4.10 requires Notified Body approval of changes that could affect safety and performance.
"An end user who modifies and then resells becomes the manufacturer."	The GPSR and the Machinery Regulation exclude consumers and non-professional users modifying for their own use, and occasional supplies by hobbyists are not in principle a commercial activity under the Blue Guide.
"FCC Class II covers any RF change under the same FCC ID."	Class II covers changes that degrade reported performance while still meeting the rules; changes to the basic frequency circuitry, modulator or maximum power rating need a new grant, unless they are Class III software changes on a software defined radio.

Practical pitfalls

• Assuming a firmware update is always maintenance. A feature update that modifies intended functions or the radio interface and increases risk is substantial under the Blue Guide and RED Guide, and under the CRA any change affecting an Annex I Part I requirement is. Put the test into the release gate.
• Ignoring the rebranding rule. A distributor or refurbisher that sells under its own name becomes the manufacturer of a new product.
• Treating "equivalent" too loosely on parts. The safe zone is identical or similar parts within the originally conceived envelope. Document that envelope at design stage.
• Re-testing everything, or nothing. The texts allow re-testing only what the change affects, but the modifier must demonstrate why the rest is unaffected.
• Forgetting the Notified Body. Where a certificate exists, MDR Annex IX section 4.10 and CRA recital 41 expect the Notified Body to be informed before the change.
• Losing the MDR legacy status. A significant change in design or intended purpose of a legacy device ends the Article 120 transition for it.

A worked example

Case: a connected industrial sensor, self-declared under the RED

A Wi-Fi sensor was placed on the market under the RED and RoHS, its EMC obligation covered by RED Article 3(1)(b) because Directive 2014/30/EU does not apply to radio equipment covered by the RED. The manufacturer applied harmonised standards in full and used internal production control with presumption of conformity.

• Scenario A, security patch. A firmware update closes a vulnerability and keeps every assessed behaviour. Not substantial under the Blue Guide or the RED Guide, and expressly not under CRA recital 39. Record the patch in the technical documentation.
• Scenario B, new radio band. A firmware update enables a sub-GHz transmit mode the original assessment never covered. The radio interface and performance change in a way not foreseen, and the radio risks (spectrum use, exposure) change. Substantial: re-assess the radio scope, update the technical documentation, issue a new declaration of conformity. Internal production control remains available under RED Article 17(3) if cited harmonised standards are applied in full for Article 3(2); otherwise EU-type examination or full quality assurance applies.
• Scenario C, refurbisher upgrade. A third party rebuilds returned units with a higher-power radio module and resells them under its own brand. Both the rebranding rule and the three conditions apply: the refurbisher is the manufacturer of a new product, with its name and address on it.

From 11 December 2027, the manufacturer of scenario B also has to check the CRA definition: a new radio mode that changes the attack surface affects compliance with Annex I Part I and is a substantial modification under Article 3(30).

See also

• GPSR: the General Product Safety Regulation
• Cyber Resilience Act (CRA)
• Machinery Directive 2006/42 and Regulation 2023/1230
• MDR: the Medical Device Regulation
• FCC ID, Grantee Code & TCB: equipment authorization
• EU AI Act: product compliance for manufacturers
• Technical documentation file: required contents

Working on deciding whether a product change is a substantial modification for a real product? AESTECHNO can audit your design and certification plan. Get in touch

Sources & references

1. Commission Notice: The Blue Guide on the implementation of EU product rules 2022 (OJ C 247, 29.6.2022), section 2.1, EUR-Lex eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:52022XC0629(04)
2. Regulation (EU) 2023/1230 on machinery, Articles 3(16), 17, 18 and 54, EUR-Lex eur-lex.europa.eu/eli/reg/2023/1230/oj
3. Regulation (EU) 2024/2847 (Cyber Resilience Act), Articles 3(30), 21, 22, 26, 69 and 71, recitals 39 to 42, EUR-Lex eur-lex.europa.eu/eli/reg/2024/2847/oj
4. Regulation (EU) 2023/988 on general product safety (GPSR), Article 13, EUR-Lex eur-lex.europa.eu/eli/reg/2023/988/oj
5. Directive 2014/53/EU (Radio Equipment Directive), Articles 14 and 17, EUR-Lex eur-lex.europa.eu/eli/dir/2014/53/oj
6. Guide to the Radio Equipment Directive 2014/53/EU (July 2026 version), section 1.5 Repairs, software updates, European Commission single-market-economy.ec.europa.eu/document/download/a0c7e4c5-27db-4c59-9c43-a380ed21563f_en?filename=RED%20Guide%20-%20version%2007.07.2026%20-%20with%20COVER.pdf
7. Regulation (EU) 2017/745 on medical devices (MDR), Articles 2(30), 2(31), 16 and 120, Annex IX section 4.10, EUR-Lex eur-lex.europa.eu/eli/reg/2017/745/oj
8. Regulation (EU) 2023/607 amending the MDR transitional provisions (Article 120(3) to 120(3c)), EUR-Lex eur-lex.europa.eu/eli/reg/2023/607/oj
9. MDCG 2020-3 Rev.1: Guidance on significant changes regarding the transitional provision under Article 120 of the MDR (May 2023), European Commission (MDCG) health.ec.europa.eu/document/download/800e8e87-d4eb-4cc5-b5ad-07a9146d7c90_en?filename=mdcg_2020-3_en_1.pdf
10. Regulation (EU) 2019/1020 on market surveillance, EUR-Lex eur-lex.europa.eu/eli/reg/2019/1020/oj
11. 47 CFR 2.1043 Changes in certificated equipment, eCFR www.ecfr.gov/current/title-47/chapter-I/subchapter-A/part-2/subpart-J/section-2.1043