WorkflowEU

EU Machinery Regulation substantial modification workflow

This workflow is relevant when a physical or digital change may affect the safety of machinery or a related product after it has been placed on the market or put into service.

The Regulation's definition and Article 18 duties generally apply from 20 January 2027. Earlier modifications must be assessed under the Machinery Directive framework and applicable national law and guidance.

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Author

Sorena AI

Published

May 9, 2026

Updated

Jul 25, 2026

Sections

Structured answer sets in this page tree.

Primary sources

Cited legal and guidance references.

Publication metadata

Sorena AI

Published May 9, 2026

Updated Jul 25, 2026

Overview

For a assessed under Regulation (EU) 2023/1230 from 20 January 2027, capture what changed, test it against the complete Article 3(16) definition, decide whether the modifier takes manufacturer obligations for the affected machinery or related product, and retain the supporting risk and conformity evidence. For an earlier modification, do not apply Article 3(16) retroactively; use Directive 2006/42/EC, applicable national law, and the Commission's Directive guidance on machinery modified into de facto new machinery.

Section 1

1. Identify the modification before judging it

Open the file with a change record that shows the product model, serial or configuration range, market status, and whether the change is physical, digital, or both. The definition applies after machinery or a related product has been placed on the market or put into service, so the record should distinguish a post-market or in-service change from ordinary design work before first release.

Describe who will carry out the change, whether the original manufacturer foresaw or planned it, and whether the change affects the whole machine, a related product, or only a part of an assembly of machinery. That scope matters because Article 18 ties the modifier's manufacturer obligations to the machinery or related product affected by the , as demonstrated in the risk assessment.

Record the modification type: mechanical, electrical, control-system, software, firmware, safety-function, guard, protective-device, stability, load, speed, operating-mode, or operating-environment change.
Record the baseline: original instructions, intended use, limits of use, existing safeguards, applicable EHSRs, standards or common specifications used, EU declaration of conformity, and technical documentation reference.
Record the affected boundary: whole product, related product, partly affected assembly, safety component, control system, guard, protective device, or stability/mechanical-strength element.
Record whether the change was foreseen or planned by the manufacturer; if it was not, move to the hazard and risk impact test.

Sources for this answer

Regulation (EU) 2023/1230 on machinery

Article 3(16) defines substantial modification and Article 18 assigns manufacturer duties for the affected machinery or related product. Article 54 makes those rules generally applicable from 20 January 2027.

European Commission machinery sector page

Commission sector context explains that existing machinery can be modified to such an extent that it becomes de facto new machinery.

Section 2

2. Test whether the change creates a substantial modification

Apply the definition as a threshold test. A change should be treated as substantial only when the change was not foreseen or planned by the manufacturer, affects safety by creating a new hazard or increasing an existing risk, and requires one of the protective responses named in the Regulation.

Do not treat every service activity as substantial. The Regulation's recitals distinguish repair and maintenance operations that do not affect compliance with the relevant essential health and safety requirements from substantial modifications. A change that was foreseen or planned by the manufacturer also fails the Article 3(16) definition, but the manufacturer must still keep series production, risk evidence, instructions, and the declaration aligned where the planned change affects conformity.

Hazard trigger: identify each new hazard introduced by the modification, including hazards from software, control logic, changed use, new access points, changed energy, changed loads, or changed interaction with operators.
Risk trigger: identify each existing risk that increases, recording the change in severity, probability, exposure, avoidance, stability margin, mechanical strength, or control reliability.
Protective-measure trigger: check whether the change requires adding guards or protective devices whose processing requires modifying the existing safety control system.
Stability or strength trigger: check whether additional protective measures are needed to ensure stability or mechanical strength.
Non-substantial outcome: if the change is repair or maintenance and the evidence shows no effect on compliance with relevant EHSRs, record that rationale and keep the evidence with the service file.

Sources for this answer

Regulation (EU) 2023/1230 on machinery

Article 3(16) supplies the substantial-modification elements: not foreseen or planned, safety affected, new hazard or increased risk, and specified protective measures.

ISO 12100:2010 - Safety of machinery

ISO 12100 cited sources support a structured hazard-identification, risk-estimation, risk-evaluation, risk-reduction, documentation, and verification approach for machinery safety work.

Section 3

3. Check the personal-use exception before assigning the manufacturer role

Article 18 contains a narrow actor exception. A non-professional user who carries out a to his or her machinery or related product for personal use is not considered a manufacturer under Regulation (EU) 2023/1230 and does not take the Article 10 manufacturer obligations through Article 18.

Do not extend this exception to a company, employer, professional user, service provider, integrator, or person modifying machinery for another user or for market supply. The exception also does not decide duties under workplace-safety, product-liability, electrical-safety, or other applicable Union or national law.

Record whether the modifier is a natural person acting outside professional activity or work.
Record whether the machinery is modified solely for that person's own use rather than for sale, supply, an employer, a client, or another user.
If either fact is uncertain, do not close the actor analysis; identify the applicable Member State rules and obtain case-specific advice.

Sources for this answer

Regulation (EU) 2023/1230 on machinery

Article 18 states the non-professional user's own-use exception and defines its consequence under the Machinery Regulation.

Section 4

4. If substantial, treat the modifier as the manufacturer for the affected scope

When the threshold is met, Article 18 treats the natural or legal person carrying out the as the manufacturer for the machinery or related product concerned. If only part of an assembly is affected, the scope can be limited to the affected machinery or related product, but the risk assessment must demonstrate that boundary.

The modifier should then stop treating the activity as a maintenance closeout and run the manufacturer-obligation workstream for the affected scope. That includes ensuring conformity with applicable requirements, applying the relevant conformity assessment procedure, and declaring conformity on its own responsibility.

Name the Article 18 responsible person or legal entity and the affected machinery or related product.
Update the risk assessment to show the modified hazards, increased risks, protective measures, and any unaffected parts of an assembly.
Map applicable EHSRs from Annex III to the modified design, construction, safeguards, control functions, instructions, and safety information.
Decide whether other Union harmonisation legislation covers some risks more specifically, because the Machinery Regulation does not apply to those risks to the extent that the specific legislation covers them.

Sources for this answer

Regulation (EU) 2023/1230 on machinery

Article 18 states that the person carrying out a substantial modification is considered the manufacturer and must apply manufacturer obligations for the affected machinery or related product.

Section 5

5. Rebuild the conformity file before release or use

For a , the evidence file should be rebuilt around the modified scope. Article 10 requires the manufacturer to ensure design and construction against Annex III EHSRs, draw up technical documentation, carry out or have carried out the relevant conformity assessment, then draw up the EU declaration of conformity and affix the CE marking after conformity has been demonstrated.

Select the conformity assessment route under Article 25 for the affected machinery or related product. Annex I Part A categories require the specified procedures involving a notified body route; Annex I Part B allows internal production control only when the machinery or related product was designed and constructed according to the relevant harmonised standards or common specifications covering all relevant EHSRs; products not listed in Annex I use internal production control.

Risk assessment: update hazard identification, risk estimation, risk evaluation, risk reduction, verification, and the affected-scope boundary.
EHSR matrix: mark each Annex III requirement as applicable, not applicable with rationale, met by design, met by protective measure, met by information, or requiring open action.
Technical documentation: update drawings, calculations, control logic, software or programming-logic references where relevant, test reports, standards or common specifications, instructions, and verification records.
Conformity assessment: document the Article 25 route, notified body involvement where required, certificates or approvals where applicable, and why the selected route fits the modified product category.
Declaration and CE marking: issue or update the EU declaration of conformity for the modified machinery or related product and affix CE marking only after conformity has been demonstrated.

Sources for this answer

Regulation (EU) 2023/1230 on machinery

Articles 10 and 25 ground the manufacturer workstream: EHSRs, technical documentation, conformity assessment, EU declaration of conformity, and CE marking.

Single Market Compliance Space - notified bodies by legislation

Grounds where teams can check notified bodies for conformity assessments under listed EU legislation, including machinery entries.

Recommended next step

Turn the modification decision into an evidence file

Use the workflow to record the change, hazard and risk impact, affected scope, conformity route, declaration, CE-marking status, and release evidence for the modified machinery or related product.

Research workflow

Open Research Copilot

Check Machinery Regulation scope, evidence, and conformity-assessment questions with cited outputs.

Explore next step

Talk to Sorena

Talk through implementation

Review your modification facts, risk assessment, EHSR matrix, technical documentation, and release evidence.

Explore next step

Section 6

6. Keep the substantial modification evidence pack

Close the workflow only when the file explains both the decision and the release state. The evidence should let a reviewer see why the change was or was not substantial, what hazards or risks changed, which product boundary was affected, and which conformity work was completed before the modified machinery or related product was placed on the market or put into service.

For substantial modifications, keep the updated technical documentation and EU declaration of conformity available for market-surveillance authorities for the required retention period. Keep unaffected-assembly evidence too, because the Regulation allows avoiding repeated tests and new documentation for machinery or related products in an assembly that are not affected by the modification.

Change record with product identity, baseline configuration, modification description, implementer, affected boundary, and whether the change was foreseen or planned.
Substantial-modification test showing new hazards, increased risks, guards or protective devices affecting safety controls, stability or mechanical-strength measures, and the final threshold decision.
Risk assessment and EHSR matrix for the affected machinery or related product, including rationale for any assembly parts treated as unaffected.
Technical documentation index with drawings, calculations, control-system and software records, standards or common specifications, test and inspection evidence, instructions, and safety information.
Conformity assessment record, notified body correspondence or certificates where applicable, EU declaration of conformity, CE-marking evidence, release approval, and authority-response log.

Sources for this answer

Regulation (EU) 2023/1230 on machinery

Grounds retention of technical documentation and EU declaration of conformity, plus the recital that unaffected assembly parts should not require repeated tests or new documentation.

ISO 12100:2010 - Safety of machinery

Supports documenting and verifying the risk assessment and risk-reduction process in the evidence pack.

Primary sources

References and citations

European Commission machinery sector page

single-market-economy.ec.europa.eu

Referenced sections

Commission sector context explains that existing machinery can be modified to such an extent that it becomes de facto new machinery.

"becomes de facto new machinery"

ISO 12100:2010 - Safety of machinery

iso.org

Referenced sections

Supports documenting and verifying the risk assessment and risk-reduction process in the evidence pack.

"documentation and verification"

Regulation (EU) 2023/1230 on machinery

eur-lex.europa.eu

Referenced sections

Grounds retention of technical documentation and EU declaration of conformity, plus the recital that unaffected assembly parts should not require repeated tests or new documentation.