What is the difference between a directive, a regulation and a standard?

A directive (for example the RED) sets binding objectives that each member state transposes into national law. A regulation (for example RoHS recast or the CRA) applies directly in every member state without transposition. A standard (for example EN 300 328) is a voluntary technical specification written by a recognised standards body. Only directives and regulations are law. A standard becomes legally meaningful for CE marking when the European Commission cites it in the Official Journal, which then gives it the power to grant presumption of conformity.

Does applying a harmonised standard make my product automatically compliant?

No. A harmonised standard grants presumption of conformity only for the essential requirements it covers, and only if it is applied in full. Presumption is rebuttable, market surveillance can still challenge it with evidence. You also remain responsible for any essential requirement the standard does not address, which you must satisfy by other means and document in the technical file.

What is the difference between a dated and an undated reference?

A dated reference in the Official Journal names a specific edition, for example EN 300 328 V2.2.2, and only that edition grants presumption of conformity. An undated reference points to the standard without an edition number, so the latest published edition applies. The Official Journal of the EU uses dated references, which is why a new edition does not bring presumption until the Commission updates the citation, usually with a transition period.

Is a harmonised EN standard the same as a national standard?

Not for legal purposes. A harmonised standard is one a European standards body (CEN, CENELEC or ETSI) produced under a Commission request and that the Commission then cited in the Official Journal. A national standard, such as a DIN, BS or NF document, may be identical in content (national bodies adopt EN standards under their own prefix), but only the citation in the Official Journal of the EU grants presumption of conformity.

What do I do if no harmonised standard covers my product?

You may still demonstrate conformity by other technical means, national standards, IEC or ISO standards not yet harmonised, ETSI deliverables, recognised guidance, or your own justified engineering analysis. You document the reasoning and test evidence in the technical file. For radio products under the RED, the absence or partial application of a harmonised standard usually triggers a Notified Body route under module B.

How do I confirm that a standard is still current?

Cross-check three things, the consolidated list of harmonised standards on the European Commission site and the latest implementing decision in the Official Journal, the standards body catalogue (CEN-CENELEC or ETSI) for the current edition and withdrawal status, and any transition dates attached to the citation. A standard withdrawn from the Official Journal no longer grants presumption even if the document is still purchasable.

Are harmonised standards free to download?

Following EU case law, the harmonised standards cited in the Official Journal must be accessible, and the Commission provides free read-only access to many of them. Full reusable copies are normally purchased from a national standards body (AFNOR, DIN, BSI, and others) or, for telecom standards, downloaded free from the ETSI portal. IEC and ISO base documents are sold by IEC and ISO.

Do UK designated standards work like EU harmonised standards?

They follow the same logic. After Brexit, Great Britain replaced presumption of conformity under EU harmonised standards with UK designated standards listed by the relevant UK regulator for UKCA marking. Most designated standards are identical in content to the EU harmonised versions, but the two lists are maintained separately and can diverge over time, so each market must be checked on its own list.

Harmonised standards and presumption of conformity

Author Hugues Orgitello Last updated 28 May 2026 ~12 min read

Guide · Standards and the legal framework

A recurring source of confusion in CE marking is the relationship between the law and the standards used to satisfy it. A directive or a regulation states what a product must achieve, the essential requirements. A standard describes one technically accepted way to get there. Most of the time these two layers meet through a single, precise mechanism, the presumption of conformity granted by a harmonised standard cited in the Official Journal of the European Union. This page explains that mechanism end to end, the vocabulary around it (harmonised versus national, dated versus undated, normative versus informative), and what to do in the awkward but common case where no harmonised standard fits your product.

Directive, regulation, standard: three different things

The first step is to stop treating these three words as interchangeable. They sit at different levels of the legal hierarchy and have very different force.

Instrument	Who writes it	Legal force	Example
Directive	EU legislator (Parliament and Council)	Binding objectives, transposed into national law by each member state	Directive 2014/53/EU (RED)
Regulation	EU legislator	Directly applicable in every member state, no transposition	RoHS recast, the Cyber Resilience Act
Harmonised standard	A European standards body (CEN, CENELEC, ETSI) on a Commission request	Voluntary, but grants presumption of conformity once cited in the Official Journal	EN 300 328
Other standard	National, IEC, ISO, ETSI, or industry body	Voluntary, no presumption unless adopted and cited	IEC 62368-1

The key idea: only directives and regulations are law. A standard is never mandatory in itself. You are always free to demonstrate conformity by another route. What a harmonised standard buys you is a legal shortcut, the presumption of conformity, which shifts the burden of proof in your favour.

A regulation differs from a directive mainly in how it enters force. A directive sets a result and lets each country write its own implementing law, which is why you sometimes see small national variations. A regulation is the same text everywhere on the day it applies. For the manufacturer, the practical consequence is that regulations remove the national-transposition guessing game, while the standards mechanism on top of them works identically.

What a harmonised standard actually is

A harmonised standard is not just any EN document. It is a standard that meets two cumulative conditions defined by Regulation 1025/2012, the regulation on European standardisation:

It was produced by a recognised European standards organisation (CEN, CENELEC or ETSI) in response to a formal standardisation request (a mandate) issued by the European Commission for a specific piece of legislation.
Its reference was published (cited) in the Official Journal of the European Union through an implementing decision.

Both conditions matter. An EN standard written outside a Commission request, or one that exists but has never been cited, is a perfectly valid technical document, but it does not grant presumption of conformity. The legal magic comes entirely from the citation in the Official Journal, abbreviated OJEU.

This is why two products can cite the same EN number and have very different legal standing: one applied the cited edition in full, the other applied a withdrawn edition or applied the standard only partially. The number alone tells you nothing.

The presumption of conformity mechanism

Presumption of conformity is the engine of the New Legislative Framework. The principle, set out in the Blue Guide, is simple to state:

A product that conforms to a harmonised standard whose reference is published in the Official Journal is presumed to conform to the essential requirements that standard covers.

Three words in that sentence carry the whole weight.

Presumed. The presumption is rebuttable. It puts the burden of proof on the market surveillance authority rather than on you, but an authority that finds real evidence of non-conformity can still act. Presumption is a strong default, not an unconditional shield.

Covers. A standard grants presumption only for the essential requirements it actually addresses. Annex ZA (or ZZ) of the harmonised standard maps each clause to the essential requirements of the legislation. If a requirement is not in that mapping, the standard says nothing about it and you must satisfy it some other way.

Conforms. Presumption requires that you apply the standard in full. Picking the convenient clauses and skipping the inconvenient ones does not give you presumption, it gives you a partial application that a Notified Body or an auditor will treat as a gap.

How presumption is established in the technical file

Presumption is not something you declare on a form, it is something an inspector can reconstruct from your technical documentation. To establish it cleanly, the file should make all of the following auditable:

The list of harmonised standards applied, with their exact edition and version (for example EN 300 328 V2.2.2, not just "EN 300 328").
Evidence that each standard was applied in full, the test reports covering every applicable clause, including the limits and the measurement conditions the standard prescribes.
A clause-by-clause mapping (the annex ZA table) showing which essential requirement each part of the standard satisfies.
A justification for any clause declared not applicable, with the technical reasoning.
For requirements not covered by any harmonised standard, the alternative solution and its supporting evidence.

The EU Declaration of Conformity then lists the standards relied upon. But the DoC is only the visible summary, the presumption itself lives in the test reports and the clause mapping inside the technical file.

OJEU citation: dated and undated references

The citation in the Official Journal is what activates presumption, so the exact wording of that citation matters. The Commission publishes, for each piece of legislation, an implementing decision listing the harmonised standards and how each one is referenced.

There are two referencing styles, and the difference trips up many manufacturers.

Reference type	What it names	Which edition grants presumption
Dated	A specific edition, e.g. EN 301 489-1 V2.2.3	Only that exact edition
Undated	The standard with no edition number	The latest published edition

In practice the Official Journal uses dated references for harmonised standards. This has a consequence that surprises people: when CEN, CENELEC or ETSI publishes a new edition of a standard, that new edition does not automatically grant presumption. Presumption follows only once the Commission issues a new implementing decision citing the new edition. The decision normally sets a transition period during which both the old and new editions confer presumption, after which the old one is withdrawn.

This is the single most common reason a Declaration of Conformity goes stale: the manufacturer cites the edition that was current at design time, a newer edition is later cited and the old one withdrawn, and the DoC now references a standard that no longer grants presumption. Re-checking the cited editions is part of keeping the file alive, see the RED checklist and the RED standards page for the radio-specific lists.

The standards bodies and their prefixes

The prefix on a standard tells you who maintains it and, indirectly, how it relates to CE marking. Knowing the families avoids a lot of confusion.

Prefix	Body	Scope	Harmonised for CE?
EN	CEN, CENELEC or ETSI	European standard, adopted identically across CEN/CENELEC members	Yes, if cited in the OJEU
ETSI EN	ETSI	European telecom/radio standard	Yes for the RED, if cited
IEC	IEC	International electrotechnical standard	Not directly, but often the basis of an EN
ISO	ISO	International standard, all sectors	Not directly, often basis of an EN
CISPR	CISPR (within IEC)	EMC emissions/immunity	Basis of EN 55xxx series
EN ISO / EN IEC	CEN/CENELEC adopting an ISO/IEC text	International text adopted as European	Yes, if cited
DIN, BS, NF	National bodies (Germany, UK, France)	National adoption of an EN, with a national prefix	Via the underlying EN if cited

A few relationships are worth internalising. Most EN standards in electronics are national or regional adoptions of an underlying IEC or CISPR document. For example, the EN 55032 emission standard derives from CISPR 32, and EN 62368-1 derives from IEC 62368-1. The technical content is largely the same, but only the EN edition cited in the Official Journal grants presumption for CE marking. National members (AFNOR in France, DIN in Germany, BSI in the UK) then republish the EN under their own prefix, EN, DIN EN, BS EN, NF EN, with identical content.

For radio, the relevant family is ETSI EN, for example EN 300 328 for 2.4 GHz wideband data, EN 301 489 for radio EMC, and EN 18031 for the RED cybersecurity requirements. ETSI standards are the backbone of RED presumption.

Normative versus informative content

Inside a standard, not every line carries the same weight. The distinction between normative and informative content decides what you must do to claim presumption.

Normative clauses contain the requirements. They use words like "shall" and define limits, methods and pass/fail criteria. To apply the standard in full, you satisfy every applicable normative clause. The normative annexes (often labelled "Annex A (normative)") are part of the requirements.
Informative content explains, illustrates or recommends. It uses "should" or "may", and includes informative annexes, notes and the bibliography. Informative material helps you apply the standard correctly but is not itself a requirement.
Annex ZA / ZZ is a special normative annex in harmonised EN standards. It maps the standard's clauses to the essential requirements of the legislation. This is the annex that defines exactly which essential requirements the standard covers, and therefore the precise scope of the presumption it grants.

When an auditor checks "full application", they are checking that every applicable normative clause has been met and evidenced. You do not need to follow informative recommendations to claim presumption, but ignoring a clear "should" without a reason is often a sign of a weak file.

When no harmonised standard exists

This is more common than newcomers expect. A genuinely new technology, a niche product, a combination of features no single standard anticipated, or a standard that exists but covers your product only partially, all leave you without a clean presumption route. The legislation anticipates this. Lack of a harmonised standard does not mean you cannot CE-mark, it means presumption is not handed to you and you must build the conformity argument yourself.

The options, roughly in order of how often they apply:

Apply a non-harmonised standard. An IEC, ISO or national standard, or an ETSI deliverable that has not (yet) been cited in the OJEU, is still solid technical evidence. You apply it, document the test results, and argue in the technical file that meeting it satisfies the essential requirement. You simply do not get automatic presumption.
Use recognised guidance or technical specifications. Commission guidance, CEN/CENELEC technical specifications (TS) and technical reports (TR), or industry best-practice documents can underpin the argument.
Build a justified engineering case. Where nothing fits, you demonstrate conformity directly from first principles, hazard analysis, calculation, measurement, and reasoned argument, all captured in the file. This is the most demanding route and the one most likely to be challenged.
Take the third-party route. Under the RED specifically, if the article 3.2 harmonised standards do not exist or are not applied in full, the manufacturer cannot self-declare and must involve a Notified Body for an EU-type examination (module B). The choice between self-declaration and a Notified Body is covered in detail in our self-declaration vs Notified Body guide.

In every one of these cases the burden of proof sits squarely on you. Where a harmonised standard would let an inspector accept your file on sight, the absence of one means your alternative evidence has to be complete, traceable and convincing. Accredited testing under ISO/IEC 17025, with the measurement uncertainty handled properly (see our calibration and measurement uncertainty guide), becomes even more important when you cannot lean on a cited standard.

Verifying a standard is current, and obtaining it

Two practical questions close out the workflow: how do I know the standard I plan to cite still grants presumption, and where do I actually get the document?

Checking the citation is live

Cross-check three sources before you rely on a standard:

The Commission's consolidated list of harmonised standards for the relevant legislation, plus the latest implementing decision in the Official Journal. This is authoritative for presumption.
The standards body catalogue, CEN-CENELEC or ETSI, for the current edition, the publication date and whether the edition is active or withdrawn.
The transition dates attached to the citation. During a transition window both editions confer presumption, after it only the new one does.

A standard can be on sale and fully usable as a technical reference yet withdrawn from the Official Journal, in which case it no longer grants presumption. Buying or downloading a standard tells you nothing about its OJEU status, the two are separate systems.

Where to obtain standards

Standard family	Where to obtain it	Cost
ETSI EN (radio, RED)	ETSI portal	Free download
EN (general, via CEN/CENELEC)	National body: AFNOR (FR), DIN (DE), BSI (UK), etc.	Paid, per document
Harmonised EN cited in OJEU	Free read-only access via the Commission	Free (read-only)
IEC	IEC Webstore	Paid
ISO	ISO Store or national body	Paid

Following EU case law on access to harmonised standards, the Commission now provides free read-only access to many cited harmonised standards, while reusable, printable copies are still bought from the national standards bodies. Telecom and radio standards from ETSI have always been free to download, which is convenient given how central they are to the RED.

UK designated standards: a brief parallel

After the United Kingdom left the EU, Great Britain (England, Wales and Scotland) replaced the EU presumption mechanism with its own, structurally identical one for the UKCA marking. Instead of harmonised standards cited in the Official Journal, the UK relies on designated standards listed by the relevant UK regulator. Conformity with a designated standard gives presumption of conformity to the corresponding UK regulations, exactly as in the EU.

Two points are worth remembering:

Most UK designated standards are, today, identical in content to the EU harmonised versions, because they derive from the same EN documents.
The two lists are nonetheless maintained separately and can diverge over time. A standard withdrawn or updated in one list will not necessarily move in lockstep in the other.

Northern Ireland follows a distinct arrangement under which EU rules continue to apply for goods. The practical takeaway for a manufacturer selling on both sides of the Channel: treat the EU and GB lists as two independent checks, even when the underlying standards look the same. The pillar pages CE marking overview and RED standards cover the EU side in depth.

Putting it together

For a typical product, the standards workflow reduces to a short loop. Identify the applicable directives and regulations. For each essential requirement, find a harmonised standard whose annex ZA covers it. Confirm the cited edition in the Official Journal is current and note any transition window. Apply that edition in full, gather accredited test evidence, and map clause to requirement in the technical file. For any requirement no harmonised standard covers, build and document an alternative case, and if you are under the RED with a missing or partial radio standard, plan for the Notified Body route. Finally, before you sign the Declaration of Conformity, re-verify that every cited edition still grants presumption. Done this way, presumption of conformity is not a claim you make, it is a property an inspector can verify from your file.