Harmonised standards: how presumption of conformity works

Hugues Orgitelloupdated 7 Oct 202614 min read

A harmonised standard is a European standard adopted on a Commission request (Regulation 1025/2012, Article 2(1)(c)). It gives presumption of conformity only once the Commission publishes its reference in the Official Journal, and only for the essential requirements it aims to cover, in full or in the parts you apply. This page follows the mechanism through the texts that actually define it: Regulation 1025/2012, the New Legislative Framework Decision 768/2008, the 2022 Blue Guide (section 4.1.2), the implementing decisions that have carried citations in the OJ L series since late 2018, and two judgments of the Court of Justice. It ends with the common readings those texts contradict, some of which this page used to make.

TL;DR:

• Being a harmonised standard and giving presumption are two different things. The definition is only "a European standard adopted on the basis of a request made by the Commission". Presumption needs the reference published in the OJ (Blue Guide 4.1.2.2).
• Presumption attaches to "harmonised standards or parts thereof" (Decision 768/2008, Article R8). Applying part of a standard gives presumption for that part only; full application is not a precondition.
• Citations name an exact edition. A revised edition gives presumption only from its own citation, and the superseded one keeps it until the withdrawal date the Commission sets.
• The Commission summary lists are for information and "do not as such generate legal effects". The implementing decisions in the OJ are the legal text.
• Under the RED, missing or partly applied harmonised standards for Article 3(2) or 3(3) rule out internal production control for those requirements: module B followed by C, or module H (Article 17(4)).

Directive, regulation, standard: three different things

Instrument	Who adopts it	Legal force	Example
Directive	EU legislator (Parliament and Council)	Binding, transposed into national law by each member state	Directive 2014/53/EU (RED)
Regulation	EU legislator	Directly applicable in every member state	the Cyber Resilience Act, Regulation (EU) 2024/2847
Harmonised standard	CEN, CENELEC or ETSI, on a Commission standardisation request	Voluntary; gives presumption of conformity once its reference is published in the OJ	EN 300 328
Other standard	National, IEC, ISO or other bodies	Voluntary; no presumption	IEC 62368-1

Regulation 1025/2012 defines a standard as a technical specification "with which compliance is not compulsory". What a cited harmonised standard buys is the presumption of conformity: a product that follows it is presumed to meet the essential requirements it covers. The Court of Justice added a twist in James Elliott (C-613/14, 27 October 2016): a harmonised standard whose reference is published in the OJ "forms part of EU law", so the Court can interpret it, even though it is drafted by private bodies and remains voluntary for the manufacturer.

What the texts say, article by article

Text	Provision	What it says
Regulation 1025/2012	Article 2(1)(c)	Harmonised standard: "a European standard adopted on the basis of a request made by the Commission for the application of Union harmonisation legislation". No mention of the OJ
Regulation 1025/2012	Article 10(1)	The Commission may request one or more European standardisation organisations (CEN, CENELEC, ETSI, Annex I) to draft a standard within a set deadline
Regulation 1025/2012	Article 10(2a), added by Regulation (EU) 2022/2480, applicable from 9 July 2023	Acceptance of requests, new work items and adoption, revision or withdrawal of requested standards are decided exclusively by representatives of the national standardisation bodies
Regulation 1025/2012	Article 10(6)	When a harmonised standard satisfies the requirements it aims to cover, the Commission publishes its reference "without delay" in the OJ
Regulation 1025/2012	Article 11(1)	A member state or the European Parliament can raise a formal objection; the Commission decides to publish, not publish or publish with restriction, or to maintain, maintain with restriction or withdraw the reference
Decision 768/2008/EC	Annex I, Article R8	Products in conformity with "harmonised standards or parts thereof" whose references are published in the OJ are presumed to conform to the requirements covered "by those standards or parts thereof"
Directive 2014/53/EU (RED)	Article 16	The same presumption for radio equipment, against the essential requirements of Article 3
RED	Article 17(3) and 17(4)	With cited harmonised standards applied for Article 3(2) and 3(3): modules A, B+C or H. Not applied, applied in part, or none exist: B+C or H only
RED	Article 10(5)	Manufacturers must take changes in the harmonised standards they declared against "adequately" into account
Regulation (EU) 2024/2847 (CRA)	Article 27(1), (2) and (5)	Presumption from cited harmonised standards "or parts thereof"; common specifications by implementing act as a fallback when standardisation fails, also giving presumption

How presumption of conformity works

The Blue Guide (2022 edition, OJ C 247, 29 June 2022) explains the mechanism in section 4.1.2. Four points do most of the work.

Publication starts it. "The objective of publishing the reference in the OJEU is to set the date from which the presumption of conformity takes effect." Before that, a harmonised standard "or parts thereof, does not give presumption of conformity". Publication is not automatic: the Commission checks the standard against the request and may refuse it or publish it with a restriction.

It covers what the standard aims to cover. The requirements a harmonised standard aims to cover "are usually indicated in a separate informative annex", which, the Blue Guide notes, the European standardisation organisations usually name Annex ZA, ZB or ZZ. ETSI ENs use Annex A: in EN 300 328 V2.2.2, Annex A states that compliance with the normative clauses listed in table A.1 "confers, within the limits of the scope of the present document, a presumption of conformity" with the RED, and marks each requirement U (unconditional) or C (conditional, with the condition).

Parts are enough, for those parts. The Blue Guide separates "conformity with a standard" (full application, as in voluntary certification) from presumption: "it is sufficient to apply only those provisions relating to the essential or other legal requirements aimed to be covered". If only part is applied, "the presumption of conformity exists only to the extent the harmonised standard corresponds to the essential requirements". The gap has to be closed by other means and shown in the technical documentation.

It is rebuttable, and it is not risk assessment. Manufacturers "remain fully responsible for assessing all the risks of their product in order to determine which essential (or other) requirements are relevant". A footnote adds that referring to a harmonised standard in an EU declaration of conformity without applying it "does not initiate presumption of conformity".

The European version is the one that counts. Many ENs are based on ISO or IEC texts, but the Blue Guide states that presumption "is possible only when applying the European version published by reference in the Official Journal", partly because only the European version carries the mapping to the essential requirements. EN 55032, for instance, derives from CISPR 32, and EN 62368-1 from IEC 62368-1.

What the technical file should show

Presumption is reconstructed by an inspector from your technical documentation, so the file should make these auditable:

• each harmonised standard relied on, with the exact edition cited in the OJ (for example EN 300 328 V2.2.2, not "EN 300 328") and any restriction attached to that citation;
• the test evidence for every applied clause listed in the relationship annex, including the conditional ones that apply to your product;
• if you applied only part of a standard, which part, and how the requirements outside it are met;
• for requirements no cited standard covers, the alternative specification and its evidence.

From OJ C communications to OJ L implementing decisions

Until 2018 the Commission published lists of references as communications in the OJ C series: James Elliott refers to the "C" series, and the RED summary list still carries entries published in OJ C 249 of 8 July 2016. By December 2018 citations had moved to Commission implementing decisions in the L series, which the Blue Guide now describes as the method: "Publication of references of harmonised standards is managed by means of Commission Implementing Decisions". References published earlier in the C series that have not been withdrawn still give presumption.

Date	Act	What it shows
8 July 2016	Communication, OJ C 249	Early RED references, some still in force according to the summary list generated on 7 September 2026
13 January 2017	Communication, OJ C 11	Citation of EN 300 328 V2.1.1 under the RED
21 December 2018	Implementing Decision (EU) 2018/2048, OJ L 327	Harmonised standard for websites and mobile applications (Directive 2016/2102), already an OJ L decision
19 March 2019	Implementing Decision (EU) 2019/436, OJ L 75	Machinery: publications, restrictions (EN 474-1:2006+A5:2018) and deferred withdrawals
6 February 2020	Implementing Decision (EU) 2020/167, OJ L 34	RED: cites EN 300 328 V2.2.2, sets 6 August 2021 as the end of presumption for V2.1.1
10 November 2022	Implementing Decision (EU) 2022/2191, OJ L 289	The current consolidated RED decision
30 January 2025	Implementing Decision (EU) 2025/138	Amends 2022/2191: cites EN 18031-1, -2 and -3:2024 with restrictions, for Article 3(3)(d), (e) and (f), which apply from 1 August 2025
7 September 2026	Implementing Decision (EU) 2026/2003	Latest amendment of 2022/2191 listed by the Commission (adopted 4 September 2026)

Between 2022/2191 and 2026/2003 the Commission page lists further amendments adopted on 3 October 2023, 27 November 2023, 14 May 2025, 13 August 2025 and 9 December 2025. Each amendment can add, restrict or schedule the withdrawal of references, which is why a RED file checked against the 2022 decision alone is out of date.

The summary lists are convenient but explicitly secondary. The RED page states that the summary "reproduces information already published in the L series of the OJ", is provided "for information purposes only", may be incomplete at a given time, and "does not as such generate legal effects". The RED standards page and the RED checklist cover the radio-specific references.

Dated citations and coexistence periods

Every citation in the OJ names an edition: a version number for ETSI ENs (V2.2.2), a year and amendments for CEN and CENELEC (EN 474-1:2006+A5:2018). A revised edition gives presumption only from the publication of its own reference. The Blue Guide (4.1.2.5) describes what happens to the old one:

• the Commission alone decides the date on which the superseded reference is withdrawn;
• between the citation of the new edition and that withdrawal date, both give presumption (the "transitional or coexistence period");
• the Commission can shorten that period, even to zero, "for safety or other reasons", or extend it;
• withdrawal of a superseded reference "does not automatically invalidate existing certificates issued by notified bodies", but manufacturers must follow the state of the art and act where changes are material.

Standard	Cited	Presumption ends
ETSI EN 300 328 V2.1.1	13 January 2017 (OJ C 11)	6 August 2021 (set by Decision 2020/167)
ETSI EN 300 328 V2.2.2	6 February 2020 (Decision 2020/167, OJ L 34)	no end date in the summary list of 7 September 2026

Dated and undated references also exist inside standards, in their normative references clause. ETSI ENs say it plainly: normative references "are specific, identified by date of publication and/or edition number or version number. Only the cited version applies." Undated ("non-specific") references, where the latest version applies, appear in the informative references of the same documents.

The standards bodies and their prefixes

Prefix	Body	Gives presumption?
EN	CEN or CENELEC	Only the edition cited in the OJ, under the act it is cited for
ETSI EN	ETSI	Same; most RED Article 3(2) standards are ETSI ENs
EN ISO / EN IEC	CEN or CENELEC adopting an ISO or IEC text	Same; the ISO or IEC original does not
IEC, ISO, CISPR	International bodies	No, unless adopted as an EN and cited
BS EN, DIN EN, NF EN	National bodies (Blue Guide 4.1.2.2: identical national transposition is mandatory)	Through the identical EN content

Not every standard under the RED comes from ETSI. EN 18031 (parts 1 to 3, the RED cybersecurity standards) is not an ETSI deliverable: the Commission summary list records it as "CEN EN 18031-1:2024", and the list also carries CENELEC standards such as EN 50360:2017 and EN 55035:2017. The radio EMC series EN 301 489 is ETSI.

Normative clauses and the relationship annex

• Normative clauses carry the requirements ("shall"), including normative annexes.
• Informative content explains or recommends: notes, bibliography, informative annexes.
• The relationship annex is informative, yet it fixes the scope of the presumption: Annex ZA in a CEN standard, usually Annex ZZ in a CENELEC standard (where Annex ZA commonly lists normative references to international publications), Annex A in an ETSI EN. The UK GOV.UK guidance also refers to "the informative Annex ZA/ZZ". Where the annex says a requirement is not covered, or where the OJ citation carries a restriction, there is no presumption for that requirement.

Restrictions in the citation matter as much as the annex. The RED summary list shows EN 18031-1:2024 cited with notices that the "rationale" and "guidance" sections do not confer presumption, and several EN 301 489 parts cited with a note that presumption for Article 3(1)(b) is lost if certain set-up tolerances of EN 301 489-1 V2.2.3 are applied.

What if no harmonised standard exists?

The Blue Guide (4.1.3) is direct: if no harmonised standard is applied, manufacturers must demonstrate conformity "by the use of other means of their own choice", such as national or international standards, European standards not cited in the OJ, other European standardisation deliverables, or their own specifications. They "do not benefit from the presumption of conformity" and must explain in more detail in the technical file how those specifications meet the essential requirements, for example through a deeper risk assessment or a gap analysis.

Some acts add a fallback that gives presumption:

• Common specifications. The CRA (Article 27(2)) lets the Commission adopt them by implementing act when a standardisation request was refused, missed its deadline or produced non-compliant standards, and no reference is expected within a reasonable period. Conformity with them gives presumption (Article 27(5)). The Blue Guide cites the medical device regulations, where common specifications can be mandatory.
• Third-party assessment. Under the RED, Article 17(4) requires EU-type examination followed by conformity to type (module B + C) or full quality assurance (module H) for the Article 3(2) and 3(3) requirements not covered by applied cited standards. See the self-declaration vs Notified Body guide.

Without a cited standard to lean on, accredited testing under ISO/IEC 17025 and a correct treatment of measurement uncertainty (see the calibration and measurement uncertainty guide) carry more of the argument.

Getting the documents

Family	Where
ETSI EN (most RED Article 3(2) standards, EN 301 489)	Free PDF download from ETSI
EN from CEN or CENELEC (including EN 18031)	Sold by national standards bodies (AFNOR, DIN, BSI and others)
IEC, ISO	IEC and ISO stores, or national bodies

The Public.Resource.Org judgment (C-588/21 P, Grand Chamber, 5 March 2024) annulled a Commission refusal to give access to four CEN standards (EN 71-4, EN 71-5, EN 71-12 and EN 12472). The Court held that harmonised standards "form part of EU law" and that the rule of law and transparency create "an overriding public interest" in their disclosure under Regulation 1049/2001 on access to documents. It decided the case on that ground and did not examine the copyright argument. The judgment is about access on request; it did not make CEN or CENELEC standards free to download.

UK designated standards

Great Britain runs a parallel system for UKCA marking. From 1 January 2021 the relevant Secretary of State can designate standards by publishing notices on GOV.UK; the Office for Product Safety and Standards coordinates the process, and proposals are open for 28 days for objections. Following a designated standard gives a presumption of conformity "which can be countered by evidence". Designated standards are prefixed BS, EN, EN ISO or EN IEC, and where a standard is replaced there is a transition period stated in the notice. For goods placed on the Northern Ireland market, EU harmonised standards remain the reference where EU rules apply. Check each market against its own list: see UKCA marking and the CE marking overview.

Claims the texts contradict

Claim	What the text says
A harmonised standard must be applied in full to give presumption (made by this page before October 2026)	Decision 768/2008 Article R8, RED Article 16 and CRA Article 27(1) say "harmonised standards or parts thereof"; the Blue Guide (4.1.2.3) gives presumption "only to the extent" of the parts applied
Being cited in the OJ is part of the definition of a harmonised standard (made by this page)	Article 2(1)(c) of Regulation 1025/2012 only requires adoption on a Commission request. The Blue Guide: "the definition of a harmonised standard does not contain any reference to the publication of its reference in the OJEU". Publication is what triggers presumption
The Commission consolidated list is authoritative for presumption (made by this page)	The summary "does not as such generate legal effects" and is provided "for information purposes only". The implementing decisions in the OJ L series are the legal text
Without a harmonised standard for Article 3.2, the RED forces module B (made by this page)	Article 17(4) covers Article 3(2) and 3(3), and allows module B followed by C, or module H
EN 18031 is an ETSI standard (made by this page)	The summary list records "CEN EN 18031-1:2024", cited by Decision (EU) 2025/138
UK designated standards are listed by "the relevant UK regulator" (made by this page)	The relevant Secretary of State designates them by notices on GOV.UK, with OPSS coordinating
After the 2024 judgment, harmonised standards are free (made in part by this page)	C-588/21 P annulled one refusal of access under Regulation 1049/2001 and left copyright unexamined. CEN and CENELEC standards are still sold
Applying the IEC or ISO original is enough	The Blue Guide: presumption "is possible only when applying the European version published by reference in the Official Journal"
Citing a standard on the declaration of conformity creates presumption	The Blue Guide (footnote 188): citing it without applying it "does not initiate presumption of conformity"

Putting it together

Identify the applicable acts and do the risk assessment. For each relevant essential requirement, find a harmonised standard whose relationship annex covers it, then find its reference in the latest implementing decision (not only the summary list), with any restriction and withdrawal date. Apply the cited edition, in full or in identified parts, and close any gap with other specifications. Under the RED, plan for module B + C or H wherever cited standards for Article 3(2) or 3(3) are missing or partly applied. Before signing the Declaration of Conformity, and again whenever a new amending decision appears, re-check that every edition you list still gives presumption.

See also

• Getting started with certification: where to begin
• Which EU directives apply to my product?
• Conformity assessment bodies and accreditation
• Technical documentation file: required contents
• Cyber Resilience Act
• Machinery: Directive 2006/42/EC and Regulation 2023/1230

Working on confirming which harmonised standards apply to a specific product and whether the cited editions are current for a real product? AESTECHNO can audit your design and certification plan. Get in touch

Sources & references

1. Regulation (EU) No 1025/2012 on European standardisation (Articles 2, 10, 11), EUR-Lex eur-lex.europa.eu/eli/reg/2012/1025/oj
2. Regulation (EU) 2022/2480 amending Article 10 of Regulation 1025/2012, EUR-Lex eur-lex.europa.eu/eli/reg/2022/2480/oj
3. The Blue Guide on the implementation of EU product rules 2022 (OJ C 247, 29.6.2022), section 4.1.2, European Commission eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:52022XC0629(04)
4. Decision No 768/2008/EC on a common framework for the marketing of products (Annex I, Articles R8 and R9), EUR-Lex eur-lex.europa.eu/eli/dec/2008/768/oj
5. Judgment of 27 October 2016, James Elliott Construction, C-613/14, Court of Justice of the EU (EUR-Lex) eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:62014CJ0613
6. Judgment of 5 March 2024, Public.Resource.Org and Right to Know v Commission, C-588/21 P, Court of Justice of the EU (EUR-Lex) eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:62021CJ0588
7. Harmonised standards, overview and lists of references published in the OJ, European Commission single-market-economy.ec.europa.eu/single-market/goods/european-standards/harmonised-standards_en
8. Harmonised standards for radio equipment: decisions and summary list, European Commission single-market-economy.ec.europa.eu/single-market/goods/european-standards/harmonised-standards/radio-equipment_en
9. Commission Implementing Decision (EU) 2018/2048 (harmonised standard for websites and mobile applications), EUR-Lex eur-lex.europa.eu/eli/dec_impl/2018/2048/oj
10. Commission Implementing Decision (EU) 2019/436 (harmonised standards for machinery), EUR-Lex eur-lex.europa.eu/eli/dec_impl/2019/436/oj
11. Commission Implementing Decision (EU) 2020/167 (harmonised standards for radio equipment), EUR-Lex eur-lex.europa.eu/eli/dec_impl/2020/167/oj
12. Directive 2014/53/EU (RED), Articles 10, 16 and 17, EUR-Lex eur-lex.europa.eu/eli/dir/2014/53/oj
13. Regulation (EU) 2024/2847 (Cyber Resilience Act), Article 27, EUR-Lex eur-lex.europa.eu/eli/reg/2024/2847/oj
14. ETSI EN 300 328 V2.2.2 (2019-07), Annex A, ETSI www.etsi.org/deliver/etsi_en/300300_300399/300328/02.02.02_60/en_300328v020202p.pdf
15. Designated standards (Great Britain), GOV.UK, Office for Product Safety and Standards www.gov.uk/guidance/designated-standards
16. CEN-CENELEC, European Standards, CEN-CENELEC www.cencenelec.eu/european-standardization/european-standards/
17. ETSI standards search and free download portal, ETSI www.etsi.org/standards/get-standards
18. Official Journal of the European Union, direct access, EUR-Lex eur-lex.europa.eu/oj/direct-access.html