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# CE Conformity Assessment Modules Deep Dive: The Full A-through-H1 Reference

The base guide covers the eight headline modules — A, B, D, G, H, and their closest relatives. In practice, the full module family runs to sixteen named variants, split cleanly between design-phase and production-phase roles, and the module that actually applies to your product depends on chaining rules and directive-specific restrictions that the letter names alone don't explain. This deep dive covers the full family and walks through three worked module-selection examples.

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At a glance

Module variants

16

Design-only module

Module B

Most burdensome route

Module G

Most comprehensive route

Module H1

FAQs

6

On this page

*   [1\. Design-phase versus production-phase modules](#two-phases)
*   [2\. The full module family, including the variants the basics skip](#full-family)
*   [3\. How modules chain: what can and can't follow Module B](#chaining-logic)
*   [4\. Worked example: selecting a module under RED](#worked-red)
*   [5\. Worked example: selecting a module under the Machinery Regulation](#worked-machinery)
*   [6\. Worked example: category-driven module restriction under PED](#worked-ped)
*   [7\. What the Notified Body actually does, module by module](#nb-role-by-module)
*   [8\. When to voluntarily choose a higher module than required](#choosing-higher)

## 1\. Design-phase versus production-phase modules

The [base guide on CE conformity assessment modules](/guides/ce-conformity-assessment-modules) introduces the module letters individually. The organizing idea that makes the whole system click, though, is the split between design-phase assessment and production-phase assessment — and the fact that some modules cover only one phase while others cover both.

Module B exists purely to certify a product's design — the Notified Body examines documentation and a representative sample, then issues a type certificate. It says nothing about whether every subsequent unit manufactured against that design will actually conform. That is what the production-phase modules — C, C1, C2, D, E, F — are for: each answers "how do we know ongoing production keeps matching the certified design" in a different way, ranging from pure self-declaration (Module C) to per-unit Notified Body testing (Module F).

Modules A, D1, E1, F1, G, H, and H1 skip the two-stage structure entirely and cover both design and production assessment in one continuous module, which is why they can be used standalone without a paired module. Recognizing which category a module falls into instantly tells you whether it needs a partner module to function.

## 2\. The full module family, including the variants the basics skip

Beyond the eight modules most guides cover, six additional named variants exist: A1, A2, C1, C2, D1, E, E1, and F1. Each modifies its base module with either added independent testing, added surprise audits, or removal of the requirement for a prior separate type-examination.

Module

Phase

Notified Body role

Description

Module A

Design + Production

No

Internal production control. Full self-declaration — manufacturer builds the technical file, tests against applicable requirements, and signs the DoC with no external check.

Module A1

Design + Production

Accredited lab

Module A plus specific product tests carried out by an accredited internal or external laboratory — not necessarily a Notified Body, but an independently accredited test facility.

Module A2

Design + Production

Yes — surprise audits

Module A plus a Notified Body carrying out unannounced product checks at random intervals during production, without full production-phase supervision.

Module B

Design only

Yes

EU type-examination. The Notified Body examines the technical documentation and a representative sample, then issues an EU Type-Examination Certificate. Always paired with a production-phase module.

Module C

Production only (follows B)

No

Conformity to type based on internal production control. The manufacturer declares conformity to the type certified under Module B, with no NB involvement in production.

Module C1

Production only (follows B)

Accredited lab

Module C plus product testing by an accredited laboratory, without full NB production supervision.

Module C2

Production only (follows B)

Yes — surprise checks

Module C plus Notified Body random product checks at unannounced intervals — the production-phase equivalent of Module A2, but requiring prior Module B type-examination.

Module D

Production only (follows B)

Yes — full QMS audit

Conformity to type based on quality assurance of the production process. The Notified Body audits and continuously supervises the manufacturer's production, final inspection, and testing QMS.

Module D1

Design + Production

Yes — full QMS audit

The standalone version of Module D — same production QMS audit and supervision, but without requiring a prior separate Module B type-examination. Used where no design-phase certificate is mandated.

Module E

Production only (follows B)

Yes — QMS audit

Conformity to type based on product quality assurance. Narrower than Module D — the audited QMS covers final product inspection and testing specifically, not the full production process.

Module E1

Design + Production

Yes — QMS audit

The standalone version of Module E, without requiring a prior Module B. Covers final inspection and testing QMS only.

Module F

Production only (follows B)

Yes — per-unit or statistical

Conformity to type based on product verification. The Notified Body examines and tests every individual product, or uses statistical sampling, to verify conformity to the certified type.

Module F1

Design + Production

Yes — per-unit or statistical

The standalone version of Module F — includes design examination without requiring a separate prior Module B.

Module G

Design + Production, per unit

Yes — every single unit

Unit verification. The Notified Body examines the design and tests each individual product before it can be placed on the market. The most burdensome route, generally reserved for one-off products, bespoke installations, or highest-risk categories.

Module H

Design + Production

Yes — full QMS audit

Full quality assurance. The manufacturer's comprehensive QMS covers design, manufacture, final inspection, and testing, with ongoing NB audit and surveillance — no separate design certificate needed.

Module H1

Design + Production

Yes — full QMS audit + design exam

Module H plus an explicit Notified Body examination of the design itself, layered on top of the full QMS audit — the most comprehensive standalone route available.

## 3\. How modules chain: what can and can't follow Module B

Module B is a pure design-phase module and always needs a production-phase partner: C, C1, C2, D, E, or F. The choice among those six determines how much ongoing scrutiny production receives, from none (Module C, pure self-declaration against the certified type) to continuous per-unit Notified Body testing (Module F).

The standalone variants — D1, E1, F1 — exist specifically for directives that want the same production-phase rigor as D, E, or F, but without mandating a separate upfront Module B certificate. This matters in practice because it changes the timeline: a B+D route requires completing type-examination before production QMS auditing can meaningfully begin, while D1 lets a manufacturer's QMS be audited and approved without waiting on a separate design certificate first.

Module G and Module H/H1 sit outside this chaining logic entirely — they are complete, self-contained routes covering design and production together, which is precisely why they cannot be mixed with a separate Module B certificate the way C, D, E, and F can.

## 4\. Worked example: selecting a module under RED

Radio Equipment Directive module selection illustrates how the presence or absence of applicable harmonised standards, not just the product category, drives the outcome.

### RED-covered smart speaker with Wi-Fi and Bluetooth

Module A

For most RED products, harmonised standards exist and are used, so Module A internal production control is available and is the standard route — the manufacturer self-declares against the applicable RED essential requirements using the harmonised standards, no NB involvement required.

### RED product with no applicable harmonised standard, or where the manufacturer departs from one

Module B + C, or Module H

Where harmonised standards don't fully cover the product, or the manufacturer chooses not to apply them, Module A is no longer available in the same low-friction way — RED pushes such products toward Notified Body involvement through B+C or H to compensate for the absence of a standards-based presumption of conformity.

## 5\. Worked example: selecting a module under the Machinery Regulation

Machinery module selection is a cleaner category-based split: whether the specific machine type appears on the high-risk annex list is close to the whole decision.

### Non-Annex IV machinery (a standard industrial conveyor)

Module A

Machinery outside Annex IV's high-risk category list can generally self-certify under internal production control, provided applicable harmonised standards are used and followed correctly.

### Annex IV machinery (a power press or certain woodworking machines)

Module B + C, Module G, or Module H

Annex IV lists machinery categories judged inherently higher-risk. For these, Module A internal production control is not available — the manufacturer must use a Notified-Body-backed route, with the specific choice among B+C, G, or H depending on production volume and whether harmonised standards are fully applied.

## 6\. Worked example: category-driven module restriction under PED

Pressure Equipment Directive module choice is the most granular of the three, since it is directly indexed to a four-tier risk category system covering both the lowest-risk and highest-risk pressure equipment on the market.

### Pressure equipment, Category I (lowest PED risk band)

Module A

The lowest PED risk category permits full self-declaration, reflecting the comparatively low hazard potential of the smallest, lowest-pressure equipment covered by the directive.

### Pressure equipment, Category IV (highest PED risk band)

Module B+D, B+F, B+G, or H1

The highest PED category — equipment combining large volume, high pressure, and hazardous contents — restricts module choice to the most rigorous available combinations, all involving substantial Notified Body design and production oversight.

## 7\. What the Notified Body actually does, module by module

Not all Notified Body involvement is equal, and treating "NB required: yes" as a single undifferentiated fact obscures real differences in cost, timeline, and ongoing obligation. A2 and C2 involve only unannounced surprise checks at intervals — a relatively light ongoing burden. D, D1, E, and E1 involve continuous QMS audit and surveillance — a recurring relationship with the Notified Body that persists for as long as the product stays in production. F and F1 involve direct testing of individual products or statistical samples, adding per-batch time and cost to every production run. G involves examining every single unit — the most resource-intensive route, generally reserved for low-volume or one-off products where that cost is proportionate.

Budgeting for a Notified-Body-backed route means budgeting for the specific module's ongoing relationship, not just the one-time cost of an initial certificate — a mistake that shows up most often when manufacturers price out Module B+D as if it were a single upfront fee rather than an initial certification plus a recurring audit relationship for the life of production.

## 8\. When to voluntarily choose a higher module than required

Where a directive makes Module A available, choosing it is entirely legitimate — but it means the manufacturer alone carries the technical and legal weight of the compliance claim, with no independent certificate to point to if that claim is ever challenged. Some manufacturers deliberately choose a higher module even when Module A would suffice, for reasons that go beyond the letter of the law.

A Notified Body certificate can materially help in product liability disputes, since it demonstrates an independent third party reviewed the design before it reached the market. It can also smooth commercial relationships — some B2B buyers, public-sector tenders, and insurers specifically look for third-party-verified conformity, treating a self-declared DoC as a weaker signal even where it is fully legally sufficient.

The trade-off is real, though: a voluntary Module B+C or H route adds cost and lead time that a Module A route does not carry. This is a genuine business decision, not a compliance requirement, and it is worth revisiting periodically as a product line matures — a manufacturer might reasonably self-certify a first-generation product under Module A and move a mature, high-volume successor to a Notified-Body-backed route once the commercial case for that added credibility outweighs the added cost. Common DoC errors that undermine either route — outdated standard references, unclear scope — are covered in [CE Declaration of Conformity: common mistakes to avoid](/guides/ce-doc-common-mistakes).

## Frequently asked questions

### What is the difference between Module D and Module D1?

Both involve a Notified Body auditing and supervising the manufacturer's production-phase quality management system on an ongoing basis. The difference is what precedes them: Module D is a production-phase module that must follow a separate Module B type-examination establishing the certified design. Module D1 is the standalone version — it includes the production QMS audit without requiring that prior Module B certificate, because the directive it's used under does not mandate separate design-phase certification.

### Why do some directives not offer Module A at all?

Module A availability is set directive by directive, and generally correlates with how directly self-declaration can be trusted to catch the relevant risks. Directives protecting against risks that are hard to verify through documentation review alone — like MID's metrological accuracy claims, or PED's higher pressure-equipment categories — tend to restrict or exclude Module A, requiring some form of Notified Body involvement instead.

### Can Module G be combined with a separate type-examination like Module B?

No. Module G is inherently a combined design-and-production route where the Notified Body examines both the design and every individual manufactured unit — it is not built to chain after a separate Module B certificate the way Modules C, D, E, and F are. Module G stands alone as its own complete route, which is part of why it is reserved for one-off or very low-volume production where a type-based certificate covering multiple future units would not make practical sense.

### Is Module A1 the same thing as Module A with extra paperwork?

No — Module A1 requires actual independent testing by an accredited laboratory for specific characteristics defined by the applicable directive, not just additional internal documentation. That accredited lab does not need to be a Notified Body, but it does need to be independently accredited, which is a materially different level of external verification than pure Module A self-declaration.

### How does a manufacturer know which modules a specific product category can use?

The applicable directive's own annexes specify which modules are available for which product or risk category — this is not a manufacturer preference, and it is not the same across directives even for similarly-named modules. The base guide's directive availability table is a starting point, but the authoritative answer always comes from the specific directive text and its risk-category annexes (such as PED's Category I through IV, or the Machinery Directive's Annex IV list).

### Does using a higher module than legally required provide any real benefit?

Yes, primarily in liability and market-access terms. A manufacturer who voluntarily uses Module B+C or H where Module A would have sufficed gains an independent Notified Body certificate that can be pointed to in the event of a dispute or a product liability claim, and in some cases a Notified Body certificate smooths procurement in markets or sectors — public tenders, certain B2B relationships — where buyers specifically look for third-party-verified conformity even when the law does not strictly require it.

**Disclaimer:** This page is an educational resource only and does not constitute legal or regulatory advice. Module availability and chaining rules are set by each directive's own annexes and can be revised — always verify the current permitted modules for your specific product category and applicable directive, and work with an accredited Notified Body and qualified counsel before making certification decisions.

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