What is Decision 768/2008/EC and why is it horizontal?

It is the decision of the European Parliament and Council that codifies, in its Annex II, the eight reusable conformity assessment modules used by every CE marking directive and regulation. It is called horizontal because it imposes nothing by itself: each vertical directive (EMC, LVD, RED, ATEX, MDR, Machinery, PED) picks from this palette the modules it authorises for its products, depending on the risk class. It replaced Decision 93/465/EEC and forms, together with Regulation 765/2008 and the Blue Guide, the foundation of the New Legislative Framework (NLF).

What is the difference between modules D, E and H?

All three rely on a quality management system (QMS) audited and monitored by a Notified Body, but their scope differs. Module D covers the production QMS (close to ISO 9001 applied to manufacturing). Module E covers the QMS for final product inspection and testing, without covering the whole manufacturing process. Module H covers everything: design and production. H1 additionally adds a design examination by the NB.

Why does a directive impose several modules depending on risk class?

The NLF principle is that the intensity of external control must be proportionate to the risk presented by the product. A low-risk product (LVD domestic equipment, consumer EMC) stays in module A, that is, self-declaration. A high-risk product (ATEX zone 0, implantable medical device, passenger lift) requires B+D, B+F, G or H. The vertical directive sets the grid, the manufacturer chooses within the grid according to volume and quality maturity.

Is module H always the most cost-effective in the long run?

No. Module H requires a full QMS certified and audited annually, which represents a non-trivial fixed annual cost. It becomes cost-effective above a certain volume of certified products per year in close technical families, typically four to five references per year. For a manufacturer that releases only one or two products per year, or whose products fall under different directives, stacking B+C or B+D modules is almost always cheaper.

Can a module be changed during the product life cycle?

Yes, but it imposes a full re-evaluation under the directive. Switching from module A to module B+C after a market surveillance incident requires the manufacturer to have a specimen examined, redo the necessary tests and obtain a new type certificate. The reverse switch (from B+C to A) requires the manufacturer to justify that every applicable harmonised standard fully covers the product. In both cases, the technical documentation must be revised and the EU declaration of conformity updated. Better to choose the right module from the start.

Does variant A1 really differ from module A?

Yes. Module A is pure self-declaration, with no external intervention on the finished product. Module A1 keeps the internal control but adds, on aspects designated by the directive (typically radio tests or safety tests), supervision by a Notified Body that carries out or supervises the tests at random intervals. A2 is the fixed-interval variant. A1 is the typical RED route when an article 3.2 harmonised standard is not fully applicable to the product.

What documents are produced by each module?

Module A: technical documentation, EU declaration of conformity signed by the manufacturer. Module B: EU-type examination certificate issued by the NB, plus the examination dossier. Modules C, C1, C2: EU declaration of conformity citing the B certificate. Modules D, E, H: QMS approval certificate issued by the NB, plus annual audit reports. Module F: verification report and conformity certificate issued by the NB per batch or unit. Module G: per-unit conformity certificate issued by the NB. The final EU declaration of conformity is always signed by the manufacturer.

Conformity assessment modules A-H (768/2008/EC)

Q: What is the difference between module B and module C?

Module B is the EU-type examination: a Notified Body examines the product's design, has tests carried out on a representative specimen and issues an EU-type examination certificate. Module C is the production-side follow-up: the manufacturer self-declares, on the basis of its internal production control, that every produced unit conforms to the certified type. Neither is ever delivered in isolation: B is always combined with C, D, E or F depending on the level of production surveillance required by the directive.

Author Hugues Orgitello Last updated 27 May 2026 ~14 min read

Guide. Horizontal framework of CE marking

Decision 768/2008/EC is the horizontal text that codifies, in its Annex II, the eight conformity assessment modules reused across every CE marking directive and regulation. Each vertical text (Low Voltage, EMC, RED, ATEX, MDR, Machinery, Pressure Equipment) does not reinvent its procedures: it selects from this common palette the modules authorised for its products, depending on the risk class. This page sets out the eight modules, their variants (A1, A2, C1, C2, D1, E1, F1, H1), their use directive by directive, and the decision tree for choosing among them.

Origin: from new approach to the new legislative framework

The first generation of CE marking directives, in the 1985-1995 period, each defined its own conformity assessment procedures, sometimes incompatible from one text to another. Decision 93/465/EEC attempted a first harmonisation by publishing a grid of "modular approach" modules, but the text remained indicative and adoption uneven.

In July 2008, the European legislator published a package of three texts that together form what is known as the New Legislative Framework (NLF):

Regulation (EC) No 765/2008 on accreditation and market surveillance, which defines the rules applicable to Notified Bodies and national authorities.
Decision No 768/2008/EC on a common framework for the marketing of products, which codifies in Annex II the eight modules and their variants, in Annex III the rules for the EU declaration of conformity, in Annex IV the rules for affixing the CE marking.
Regulation (EC) No 764/2008 on the mutual recognition of goods (since replaced by Regulation 2019/515).

Decision 768/2008 has no direct effect on products: it is a reference text that vertical directives must take up and adapt. All "new approach" directives revised since 2014 (EMC 2014/30/EU, LVD 2014/35/EU, RED 2014/53/EU, ATEX 2014/34/EU, Lifts 2014/33/EU, PED 2014/68/EU, Non-automatic Weighing Instruments 2014/31/EU, and others) have aligned their annexes on the 768/2008 modules. The Blue Guide 2022 published by the Commission consolidates the transversal doctrine.

The eight modules of Annex II

Annex II defines eight base modules, identified by letters A to H, and nine variants (A1, A2, C1, C2, D1, E1, F1, H1) that are combinations or reinforcements of the base modules. The modules read along three axes:

Scope: design, production, finished product, quality system.
Actor: manufacturer's internal control or Notified Body (NB) intervention.
Output document: EU declaration of conformity signed by the manufacturer, EU-type examination certificate, QMS approval certificate, verification certificate.

Synoptic table of modules

Module	Title	Scope	NB intervention	QMS required	Main output document
A	Internal production control	Production	None	No	EU declaration of conformity
A1	A + supervised tests at random intervals	Production + designated tests	NB for tests	No	DoC + NB test report
A2	A + product checks at fixed intervals	Production + checks	NB for checks	No	DoC + NB check reports
B	EU-type examination	Design	NB examines design	No	EU-type examination certificate
C	Conformity to type, internal control	Production (post-B)	None	No	DoC citing the B certificate
C1	C + supervised tests at random intervals	Production + tests	NB for tests	No	DoC + NB test report
C2	C + product checks at random intervals	Production + checks	NB for checks	No	DoC + NB check reports
D	Production quality assurance	Production	Initial QMS audit + surveillance	Yes (production)	Production QMS certificate
D1	D without prior type examination	Production	Initial QMS audit + surveillance	Yes (production)	Production QMS certificate
E	Product quality assurance	Final inspection	Initial QMS audit + surveillance	Yes (final inspection)	Product QMS certificate
E1	E without prior type examination	Final inspection	Initial QMS audit + surveillance	Yes (final inspection)	Product QMS certificate
F	Product verification	Production (batch or unit)	Tests on each batch or unit	No	Per-batch verification certificate
F1	F without prior type examination	Production	Tests on each batch or unit	No	Per-batch verification certificate
G	Unit verification	Design + production	NB tests on every unit	No	Per-unit conformity certificate
H	Full quality assurance	Design + production	Full QMS audit + surveillance	Yes (design + production)	Full QMS certificate
H1	H + design examination	Design + production	Full QMS + design examination	Yes + design examination	QMS certificate + design certificate

Vertical reading: as one moves down the table, NB intervention deepens and cost and lead time rise. Horizontal reading: at equal NB intervention, the chosen module depends on the manufacturer's business model (unit production, batch, continuous series) and the maturity of its quality system.

Module-by-module detail

Module A: internal production control

The manufacturer prepares the technical documentation, has the necessary tests carried out in an accredited laboratory, signs the EU declaration of conformity and affixes the CE marking. No Notified Body intervenes. The NB identification number therefore does not appear next to the CE marking.

This is the default module for the majority of electronic products under EMC, LVD and RoHS. It is also the authorised module under the RED when every applicable harmonised standard (article 3.1, 3.2, 3.3) is fully applied to the product.

The manufacturer remains fully responsible for the validity of the dossier. Market surveillance authorities can demand the technical file at any time during the ten-year retention period and check the consistency between the documentation, the standards cited in the declaration and the product actually placed on the market. A missing test report, a withdrawn harmonised standard or a non-traceable component reference is enough to reopen the conformity question, even years after first marketing.

Output document: EU declaration of conformity plus technical documentation kept for ten years.

Modules A1 and A2: supervised variants

A1 adds, on aspects designated by the directive, supervised tests at random intervals carried out or supervised by an NB. A2 is the equivalent at fixed intervals (typically annually or per batch).

A1 is the typical RED variant when an article 3.2 harmonised standard is not fully applicable, for instance because it does not cover a proprietary modulation or a particular software mode. The NB then covers the tests the standard does not address.

A2 is rarer in electronics, used more for non-automatic measuring and weighing instruments.

Module B: EU-type examination

The NB examines the technical design of the product, has tests carried out on a representative specimen and issues an EU-type examination certificate (formalised in Annex II of the decision). The certificate covers the design: it says nothing about manufacturing, which will be covered by the following module (C, D, E or F).

The type certificate has a limited validity (typically five years under the RED, ten years under ATEX) after which a re-examination is required. Any substantial design change requires a revision of the certificate. The notion of substantial change is interpreted by the NB on the basis of the directive and the Blue Guide: a component replaced by an electrically equivalent reference usually does not require a revision, whereas a change of radio chipset, a switch in software architecture or a re-routing of the high-speed PCB tracks generally does.

Module B never applies alone: it is always combined with C, D, E or F to also cover the production phase. The combination chosen affects both the unit cost and the per-batch surveillance burden: B+C is the lightest, B+H1 the heaviest.

Modules C, C1, C2: conformity to type

C is the production stage following module B. The manufacturer self-declares, on the basis of its internal control, that each produced unit conforms to the certified type. No additional NB intervention.

C1 adds supervised tests at random intervals (typically radio or electrical safety tests). C2 adds checks at fixed intervals.

The B+C pair is the most common third-party route for products of moderate risk: RED when self-declaration is not enough, Machinery Annex IV in unit production, ATEX category 2 in gas zones, and so on.

Modules D and D1: production quality assurance

The NB audits and approves the quality management system (QMS) the manufacturer applies to production, final control and testing. The structure is close to an ISO 9001 targeted on the product in question, with specific requirements on product documentation, component traceability and record retention. The audit typically covers incoming inspection of critical components, in-process inspection, calibration of test equipment, handling of non-conforming product, and operator competence records.

Initial approval lasts three years renewable, with annual surveillance audits. Surveillance audits are unannounced or announced depending on the directive and the NB policy. A surveillance finding can trigger corrective actions, a re-audit or, in serious cases, suspension of the certificate.

D normally follows a type examination B. D1 is the variant without prior type examination: the QMS then also covers design, but with a narrower scope than a full module H. D1 is sometimes chosen when a directive does not require a B step but the manufacturer still wants a third-party QMS attestation for production.

Modules E and E1: product quality assurance

E covers the QMS for final inspection and testing of the product, rather than the whole manufacturing process. The manufacturer may subcontract production while retaining responsibility for final inspection, which will be audited by the NB.

E1 is the variant without prior type examination, applicable to products where manufacturing quality essentially plays out at final inspection (measuring instruments, certain non-implantable medical equipment).

Modules F and F1: product verification

The NB carries out tests on each batch (statistical verification) or on each unit produced. No QMS is required, but the per-unit cost is higher. Suited to small critical runs: industrial prototypes, special pressure equipment, single-unit lifts.

F1 is the variant without a prior type examination B, where the NB covers design and production on each batch.

Module G: unit verification

The NB examines the design and carries out tests on every individual unit before it is placed on the market. Suited to high-value single pieces: bespoke pressure vessels, ATEX equipment for specific installations, single-unit lifts. High cost per unit, justified by the absence of series production.

Modules H and H1: full quality assurance

H is the most complete module: the NB audits and monitors a QMS that covers design and production. There is no prior type examination: the QMS itself guarantees the coherence between essential requirements and delivered product. The QMS scope includes design control procedures, design reviews, design verification and validation records, change control, configuration management, supplier qualification, production controls and final inspection, all under documented procedures audited by the NB.

H1 adds a design documentation examination by the NB, formalised by a design examination certificate, on top of the QMS audit. It is the most demanding option in Annex II, used in particular for lifts and certain pressure equipment categories. The design examination focuses on the parts of the product where harmonised standards do not provide full coverage, and where the NB must assess directly the technical solutions retained by the manufacturer.

H and H1 are only cost-effective above a certain volume: the QMS is justified only if several products or versions share the same quality infrastructure. A manufacturer that already operates an ISO 9001 or ISO 13485 system can usually extend it to module H with a moderate gap analysis, rather than building a parallel quality system from scratch.

Modules authorised by directive

Each vertical directive picks from the 768/2008 palette the modules it authorises, generally based on a grid of risk classes. The following table summarises the options offered by the main CE marking directives.

Directive or regulation	Available modules	NB mandatory?
Directive 2014/35/EU (LVD)	A only	No
Directive 2014/30/EU (EMC)	A only	No
Directive 2014/53/EU (RED)	A, A1, B+C, H	Depends on harmonised standards application
Directive 2011/65/EU (RoHS)	A only	No
Directive 2014/34/EU (ATEX)	B+C1, B+D, B+E, B+F, G, H by category	Yes for categories 1 and 2
Directive 2014/68/EU (PED, pressure equipment)	A, A2, B+C2, B+D, B+E, B+F, D1, E1, G, H, H1 by category	Yes from category II
Directive 2014/33/EU (Lifts)	B+E, B+D, B+F, G, H1	Always
Directive 2006/42/EC (Machinery)	A for most, B+C or H for Annex IV	Yes for Annex IV
Regulation 2017/745 (MDR, medical devices)	Annexes IX, X, XI by class	Yes from class IIa
Directive 2014/31/EU (non-automatic weighing instruments)	B+D, B+F, G	Always
Regulation 2023/1542 (batteries)	A, B+C, B+D, H by type	Yes for some categories

Reading the table: a typical IoT product (mains-powered Wi-Fi/BLE connected sensor) falls under EMC + LVD + RED + RoHS. EMC, LVD and RoHS impose module A. RED leaves the choice. If the RED harmonised standards fully cover the product, module A is enough everywhere, with no NB intervention.

Detailed case: RED 2014/53/EU

The RED best illustrates the mechanics of module choice for electronics. Annex II describes module A, Annex III the partial A1, Annex IV the B+C pair, Annex V module H. The manufacturer picks the one that matches its technical situation:

Module A (Annex II) when every article 3.1, 3.2 and 3.3 harmonised standard is fully applied.
Module A1 (Annex III) when an article 3.2 standard is not fully applicable. An NB supervises the radio tests not covered by the standard.
Module B+C (Annex IV) when the product uses proprietary modulation, SDR, or modes not covered by the applicable ETSI standards. The NB issues an EU-type examination certificate.
Module H (Annex V) when the manufacturer runs a family of radio products under a certified full QMS.

Detailed case: ATEX 2014/34/EU

ATEX relies on a product + category grid. For electrical equipment in gas zones:

Category 1 (zone 0 or 20): B+D or B+F or G mandatory. Very high level of NB intervention.
Category 2 (zone 1 or 21): B+C1 or B+E or B+F or H depending on the product.
Category 3 (zone 2 or 22): module A possible (internal control), with deposit of the technical file at an NB for record retention.

ATEX illustrates the NLF principle: the more dangerous the zone, the heavier the module.

Detailed case: MDR 2017/745

The MDR does not use the A-H nomenclature, but its Annexes IX, X, XI draw directly on Annex II of Decision 768/2008:

Annex IX: assessment based on a QMS and an assessment of the technical documentation (close to a module H1).
Annex X: EU-type examination (close to a module B).
Annex XI: batch verification of conformity (close to a module F).

The choice depends on class (I, IIa, IIb, III) and device nature (implantable, measuring, sterile, etc.). Every device above class I requires an NB.

Decision tree: choosing the right module

The following path, in four questions, narrows down the relevant module for a given product.

Step 1. Identify the applicable directives

List every CE marking directive and regulation that applies to the product. A mains-powered IoT sensor typically falls under EMC + LVD + RED + RoHS. An industrial ATEX zone 1 device will add directive 2014/34/EU. A connected medical device will add the MDR. This step is decisive: a missing module means a forgotten directive.

Step 2. For each directive, read the module grid

For each applicable directive, open the annex or table that lists the modules authorised by risk class or category. EMC, LVD, RoHS impose module A: no choice. RED, ATEX, PED, Machinery, MDR offer several modules: a choice has to be made.

Step 3. Verify harmonised standards coverage

For directives that authorise module A (RED in particular), verify that every applicable essential requirement is covered by harmonised standards fully applicable to the product. This conditions the presumption of conformity. A partially applicable standard, an essential requirement not covered by any standard at all, or a standard withdrawn from the OJEU invalidates the presumption and imposes a higher module (A1 or B+C).

See our self-declaration versus Notified Body guide for the detailed technical criteria, and the CE procedure for the documentary sequence.

Step 4. Arbitrate cost, volume and quality maturity

For products where several modules are valid, the arbitrage is economic:

Unit production or small critical batches: G (unit verification) or F (per batch).
Continuous series production, single product: B+C or B+D.
Several products per year in close technical families, ISO 9001 QMS already in place: H or H1.
New product with high legal risk, even if A would technically suffice: voluntary B+C to shift part of the risk onto the NB.

The arbitrage must be documented in the quality file, in case market surveillance asks for it.

Common pitfalls

Module under-sized for the risk class

The most frequent pitfall: keeping module A for a product that falls under an ATEX 2 or MDR IIa risk class. The directive imposes an NB, self-declaration has no value, the CE marking is invalid and the product is exposed to a market recall. Always check the directive grid before concluding that A is enough.

Module B without a complete type examination

EU-type examination covers a specific design. If the manufacturer later modifies the circuit, the software or the materials without informing the NB, the certificate no longer covers the new version. The rule: every substantial modification triggers a notification to the NB, which decides whether a certificate revision is necessary.

Module H mis-sized for volume

Setting up a module H for a single product or very low volume amounts to paying a fixed annual cost (QMS audit) without obtaining the multi-product amortisation benefit. For unit production, G is more cost-effective; for a small series, B+F. Reserve H for manufacturers who certify several products per year in close families.

Late module switch

Discovering at the end of a project that the module A chosen at the start is insufficient imposes an emergency EU-type examination B+C. The NB lead time (six to sixteen weeks) adds to the schedule and postpones market entry. Better to settle the module choice at the specifications stage, before freezing the design.

Confusion between type certificate and marketing authorisation

The EU-type examination certificate attests technical compliance with the directive. It is neither a sales licence, a quality certification, nor a commercial endorsement of the product. The CE marking and the responsibility for placing on the market remain the manufacturer's.

Forgetting post-certification surveillance

Modules D, E, H require annual surveillance audits. Missing them triggers suspension of the QMS certificate, hence invalidation of the CE marking for the duration of the suspension. Surveillance is part of the NB contract and must be budgeted.

Articulation with Regulation 765/2008 and the Blue Guide

Decision 768/2008 codifies the modules; Regulation 765/2008 defines the legal framework for their execution: rules for NB accreditation, rules for notification to the Commission (NANDO database), rules for market surveillance by national authorities. Together, the two texts structure the ecosystem.

The Blue Guide 2022 published by the Commission is the transversal application handbook. It clarifies how the notions of "manufacturer", "authorised representative", "importer", "distributor" apply to the various modules, how substantial modifications are handled, and how to manage coexistence of several directives applicable to the same product.

See the CE pillar for the overview of the marking and the glossary for definitions of NLF terms.