Conformity assessment Modules A through H — the EU CE marking decision guide

Every EU directive that mandates CE marking uses one or more of the same eight conformity assessment modules defined in Decision 768/2008/EC Annex II. The modules are how the EU standardises how a manufacturer demonstrates that a product meets the essential requirements — and how, if at all, a third-party Notified Body becomes involved.

This article walks through each module from A to H, explains the typical product categories they apply to, and gives a decision guide for picking the right module.

For the broader context, see CE Marking 101 — the complete EU guide. For when a Notified Body is required, see When you need a Notified Body.

Why modules exist

Before 2008, every EU directive defined its own conformity assessment procedures. A manufacturer dealing with five directives faced five different procedures. The New Legislative Framework (NLF) — Decision 768/2008/EC plus Regulation 765/2008 — replaced that with eight standardised modules. Modern directives reference these modules by letter, so a manufacturer who learns Module A once knows what to do under LVD, EMC, RoHS, RED, CRA, and every other NLF directive that permits Module A.

The eight modules climb from least to most NB-intensive. Higher-risk products demand higher-trust assessment.

The eight modules

Module A — Internal production control (self-assessment)

"Internal production control is the conformity assessment procedure whereby the manufacturer […] ensures and declares on his sole responsibility that the products concerned satisfy the requirements of the legislative instrument that apply to them." — Decision 768/2008/EC Annex II Module A

The manufacturer performs the full assessment internally, compiles the Technical File, applies the harmonised standards, signs the Declaration of Conformity, and affixes the CE mark. No Notified Body involvement at any stage.

• Typical use: Low-Voltage Directive products that fully apply harmonised standards, EMC Directive equipment, RoHS, most consumer electronics under CRA (Module A is the default for non-Annex-III products), most RED products that fully apply harmonised standards.
• Pre-conditions: Manufacturer must apply harmonised standards listed in the Official Journal for the cited directive(s), or document equivalent conformity through other means.

Module A1 — Internal production control plus supervised product testing

Module A with one addition: a Notified Body of the manufacturer's choice tests one or more specific aspects of the product. The NB issues a test certificate for the assessed aspect; the rest of the assessment remains the manufacturer's.

• Typical use: Toys under Toy Safety Directive when one specific safety aspect needs lab confirmation but the rest is self-assessed.

Module A2 — Internal production control plus supervised product checks at random intervals

Module A with periodic spot-check by a Notified Body. The NB takes samples from the production line or the market at random intervals and verifies conformity. The manufacturer pays for the audits.

• Typical use: Personal protective equipment Category II, certain measuring instruments.

Module B — EU-type examination (design)

"EU-type examination is the part of a conformity assessment procedure in which a notified body examines the technical design of a product and verifies and attests that the technical design of the product meets the requirements of the legislative instrument that apply to it."

The manufacturer submits a representative product and Technical File to a Notified Body. The NB examines the design — by document review, by physical inspection, by testing — and if conformant, issues an EU-type examination certificate valid typically for five years.

Module B alone does not cover production. It must be combined with one of C, D, E, or F to address how each manufactured unit meets the type.

• Typical use: Radio Equipment Directive Annex IV path (where harmonised standards are not fully applied), MDR Class IIa+ devices, gas appliances, lifts, pressure equipment, ATEX equipment in higher categories.

Module C — Conformity to type based on internal production control

After Module B, the manufacturer self-attests that each manufactured unit conforms to the type examined by the NB under Module B. No further NB involvement on production.

Variants:

• C1: + supervised product testing of specific aspects by an NB

• C2: + periodic NB checks on the production line

• Typical use: B+C is common for RED products. B+C2 for ATEX equipment.

Module D — Conformity to type based on quality assurance of the production process

After Module B, the manufacturer operates an approved quality management system covering production, final product inspection, and testing. A Notified Body approves the QMS and surveils it at intervals.

• Typical use: Lifts, pressure equipment, certain MDR devices. ISO 9001 alone is not sufficient — the QMS must specifically cover the regulatory scope (CRA cybersecurity QMS, MDR medical device QMS, etc.).

Module E — Conformity to type based on product quality assurance

After Module B, the manufacturer operates an approved quality management system for final product inspection and testing only — narrower than Module D. The NB approves and surveils this final-inspection QMS.

• Typical use: Where production is outsourced but final QC is in-house and the manufacturer wants QMS rigour at the test stage.

Module F — Conformity to type based on product verification

After Module B, every manufactured unit is verified by the Notified Body (or, in F1 variant, the manufacturer + NB test certificate per unit). Used for low-volume high-risk products where a unit-level guarantee is required.

• Typical use: Custom pressure vessels, bespoke medical equipment, one-off explosives.

Module G — Conformity based on unit verification

The Notified Body verifies each single unit against the essential requirements directly, with no preceding Module B type examination. Used when the product is built one-off and there is no "type" in the usual sense.

• Typical use: Bespoke industrial machinery, custom lifts, one-off pressure vessels.

Module H — Conformity based on full quality assurance

The manufacturer operates a full quality management system covering design, manufacture, final product inspection, and testing, approved and surveilled by a Notified Body. No separate Module B — design conformity is established as part of the QMS approval.

Variant:

• H1: Module H + EU design examination certificate per product type, when the directive requires explicit design sign-off.

• Typical use: MDR Class IIb and III, IVDR high-risk diagnostics, lifts when manufacturers want long-term QMS efficiency, recreational craft. Module H is the most efficient module for mature manufacturers with continuous product evolution — once the QMS is approved, individual product changes within the QMS scope do not trigger a fresh assessment.

Module combinations

The modules are not standalone for all directives. Module B by itself addresses only design; modules C/D/E/F address production. Common combinations:

The exact combinations permitted are specified in the conformity assessment article of each directive.

Which directives use which modules

The directives' own conformity assessment articles are the authoritative source — Article 17 RED, Article 32 CRA, Annex VII MDR, and so on.

How to choose the right module

A practical decision sequence:

1. Check which modules the directive permits. Read the conformity assessment article.
2. Identify the risk class of your product within the directive. MDR Class I is Module A; MDR Class III is full Module H. CRA standard products are Module A; CRA Annex IV critical products always require Notified Body involvement and the EU cybersecurity certification scheme.
3. Check whether you fully apply harmonised standards. Most directives permit Module A when harmonised standards are fully applied. Deviation from the standards typically pushes you into Module B + something.
4. Consider production volume. For low-volume or custom products (one lift, one bespoke machine), Module G makes sense. For series production above a few hundred units per year, Module H amortises better.
5. Consider product evolution cadence. If your product evolves continuously (software updates under CRA, new SKU variants), Module H lets you handle changes within the QMS scope without re-certifying each variant individually.

How Cenitia helps with module selection

Cenitia's auto-mapper reads your product description, intended markets, and regulatory scope, then for each applicable directive identifies the permitted modules and recommends the most efficient one based on your production volume and product evolution pattern. The output is documented in the Technical File draft with the citation back to the directive's conformity assessment article.

For products that need Notified Body involvement (anything beyond Module A), our parent company Inovasense provides NB-engagement consulting and ongoing audit preparation.

Frequently asked questions

What is a conformity assessment module?

A conformity assessment module is one of eight standardised procedures (Modules A through H) defined in Annex II of Decision 768/2008/EC for demonstrating that a product meets the essential requirements of an EU directive. Each module specifies what the manufacturer must do, what evidence must be produced, and whether a Notified Body must be involved.

How do I know which module my product needs?

Each EU directive specifies which conformity assessment modules are permitted for products in its scope. The directive's conformity assessment article lists them — for example Article 17 of the Radio Equipment Directive offers Module A, B+C, or H for different scenarios. The choice depends on the risk class within the directive, whether you fully apply harmonised standards, and your production volume.

What is the difference between Module A and Module H?

Module A is full self-assessment by the manufacturer with no Notified Body involvement — the manufacturer performs internal production control and signs the Declaration of Conformity on its own authority. Module H is full quality assurance covering both design and production, audited and approved by a Notified Body — the manufacturer operates an ISO 9001-equivalent QMS with cybersecurity / safety / regulatory scope, and the NB reviews the technical design and surveils the QMS throughout the certificate's validity.

Why are modules often combined like B+C or B+D?

Module B (EU-type examination) only assesses the design of a representative type — it does not cover ongoing production conformity. Modules C, D, E, and F address production conformity in different ways: C is internal production control, D is QMS for the production process, E is QMS for final inspection, F is product verification per unit. The combination B+C, B+D, B+E, or B+F together covers both design and production over the product life.

Can I switch modules after CE marking?

Yes. If a manufacturer's production volume grows from a few hundred to many thousand units per year, moving from Module G (unit verification — every unit checked by NB) to Module H (full QMS — surveillance audits) becomes economical. The change requires reassessment under the new module — the existing CE mark on already-placed units stands; new units are assessed under the new module. Document the change in the Technical File.

Which modules involve a Notified Body?

Module A does not involve a Notified Body. Module A1 involves an NB for product testing only, A2 for periodic sampling. Modules B, D, E, F, G, and H involve a Notified Body throughout — for type examination (B), QMS audit (D, E, H), product verification (F, G). A list of EU Notified Bodies designated per directive is in the NANDO database maintained by the European Commission.

Related from the Library

• CE Marking 101 — the complete EU guide — umbrella pillar covering the whole CE marking process
• When you need a Notified Body — decision guide for the Modules B+ family
• Declaration of Conformity 101 — the document that cites the chosen module(s)

Further reading

• Decision 768/2008/EC — full text including Annex II module definitions
• Regulation 765/2008 — accreditation and market surveillance framework
• Blue Guide — implementation of EU product rules (Chapter 5 on conformity assessment)
• NANDO — EU Notified Body database

Last reviewed: 15 June 2026. Cited regulations watched continuously by Cenitia — when one amends, this article is flagged for update.