Conformity assessment — overview & route selection
Conformity assessment procedures are set out in Schedule 3 of the UK MDR 2002 (Part I general devices), Part II Schedule 3 (AIMDs), and Part III Annexes IV–VII (IVDs). The outcome of conformity assessment is the UK Declaration of Conformity and (for certified devices) the UKAB certificate, authorising the UKCA mark.
This site provides general information only. Conformity assessment involves binding decisions by UK Approved Bodies. Always consult MHRA guidance and your chosen UKAB before committing to an assessment route.
What is conformity assessment?
Conformity assessment is the systematic process by which a manufacturer demonstrates that their medical device meets all applicable Essential Requirements of UK MDR 2002. At the end of a successful conformity assessment:
- The manufacturer issues a UK Declaration of Conformity
- The manufacturer affixes the UKCA mark to the device and its packaging
- For devices requiring a UKAB: the UKAB issues a certificate that the manufacturer references in the Declaration of Conformity
Conformity assessment is the manufacturer's legal obligation — not the UKAB's. The UKAB provides third-party verification for higher-risk devices, but the manufacturer bears primary responsibility throughout.
Route selection by device class
The conformity assessment route is determined by the device's class:
General medical devices (Part I)
| Class | Conformity assessment route | UKAB involvement |
|---|---|---|
| Class I (standard) | Schedule 3, Annex VII equivalent — self-declaration | None |
| Class I (sterile) | Schedule 3, Annex VII + sterility aspects via UKAB | UKAB: sterility QMS only |
| Class I (measuring) | Schedule 3, Annex VII + measuring aspects via UKAB | UKAB: measuring/metrology only |
| Class Im (reusable surgical) | Schedule 3, Annex VII + reprocessing via UKAB | UKAB: reprocessing aspects |
| Class IIa | Annex II or Annex III + IV/V/VI | UKAB: full assessment |
| Class IIb | Annex II or Annex III + IV/V/VI | UKAB: full assessment |
| Class III | Annex II (full QMS + design dossier examination) | UKAB: full assessment + design examination |
Active implantable devices (Part II)
| Device | Route | UKAB involvement |
|---|---|---|
| All AIMDs | Full QMS + design examination (or type-examination + production QA) | UKAB: mandatory, full assessment |
IVD medical devices (Part III)
| Category | Route | UKAB involvement |
|---|---|---|
| General IVDs | Annex VII equivalent — self-declaration | None |
| Self-test IVDs | Annex III + IV equivalent | UKAB involvement required |
| Annex II List B | Annex V or Annex VI equivalent | UKAB: type-examination or QMS |
| Annex II List A | Annex IV + Annex VII (design dossier + production QA) or Annex VI | UKAB: full design examination |
The Schedule 3 conformity assessment modules
Schedule 3 of UK MDR 2002 sets out the conformity assessment procedures, organised as modules (labelled as "Annexes" in the legislative text — retained from the EU MDD structure):
Annex II — Full quality assurance system
The most comprehensive route. The UKAB audits the manufacturer's full QMS covering all phases: design, manufacture, final inspection, post-market.
For Class III and AIMDs, Annex II additionally requires design dossier examination — the UKAB formally reviews the device design and issues a Design Examination Certificate.
The UKAB issues:
- QMS Certificate (full quality assurance)
- Design Examination Certificate (for Class III / AIMD only)
Suitable for: All classes requiring UKAB assessment (IIa, IIb, III, AIMD). Most common route for complex devices.
Annex III — EC type-examination
The UKAB examines a representative sample (a "type") of the device to verify it meets the applicable ERs. The UKAB issues an EC Type-Examination Certificate (ECTE).
Following type-examination, the manufacturer must use one of:
- Annex IV (production quality assurance) — UKAB audits the production QMS
- Annex V (product quality assurance) — UKAB verifies product samples against the type
- Annex VI (declaration of conformity) — manufacturer self-declares ongoing conformity based on the type-examination
Suitable for: Class IIa, IIb. Less commonly used for Class III (Annex II is preferred).
Annex IV — Production quality assurance
UKAB audits the manufacturer's production-phase QMS (manufacturing, testing, final inspection). Used alongside Annex III type-examination or independently for some IVD routes.
Annex V — Product quality assurance
UKAB performs statistical product verification — examining and testing samples from each production batch. Less common; used where ongoing QMS assessment is not feasible (e.g., very small manufacturers).
Annex VI — Declaration of conformity based on type-examination
After UKAB type-examination (Annex III), the manufacturer self-declares that the production devices conform to the examined type. UKAB surveillance audits may apply.
Annex VII — Manufacturer's declaration (self-declaration)
Used for Class I standard devices and General IVDs. No UKAB involvement. The manufacturer:
- Prepares the technical file
- Completes the ER checklist
- Issues the UK Declaration of Conformity
- Affixes the UKCA mark
- Registers with MHRA
Choosing between Annex II and Annex III for IIa/IIb devices
Both Annex II (full QMS) and Annex III + Annex IV/V/VI (type-examination + production QA) are available for Class IIa and IIb devices. Practical considerations:
| Consideration | Annex II | Annex III + production module |
|---|---|---|
| Scope of UKAB assessment | Entire QMS (design through post-market) | Type specimen + production QMS |
| Ongoing UKAB surveillance | Annual surveillance audits of entire QMS | Surveillance of production QMS / product batches |
| Design changes | Notify UKAB; update QMS | May require new type-examination certificate |
| UKAB relationship | Single ongoing relationship covering all products | Type certificate may be product-specific |
| Common preference for | High-complexity devices with ongoing development | More stable, simpler device designs |
Most manufacturers with a range of devices prefer Annex II — a single QMS certificate covering the entire product portfolio is simpler to manage than multiple type-examination certificates.
The conformity assessment application process
For devices requiring UKAB assessment, the process typically follows these stages:
1. Pre-assessment/feasibility review
Most UKABs offer a preliminary review of the manufacturer's application pack before formal assessment. This identifies major gaps before the formal process begins and is strongly recommended.
2. Application submission
The manufacturer submits:
- Application form
- Device description and classification justification
- Current version of the technical file (or design dossier for Class III)
- QMS documentation (for Annex II routes)
- Quality manual and process documentation
- Clinical/performance evaluation report
- ER checklist
3. Document review (desktop audit)
The UKAB performs a document review — assessing the technical file against the applicable ERs and Schedule 3 requirements. Review findings are issued as a list of observations and non-conformities (NCs).
NCs are categorised:
- Major NC — must be resolved before certification; represents a significant deficiency in ER conformity
- Minor NC — must be resolved within an agreed timeframe; does not block initial certification
- Observation — noted for attention; no formal response required
4. On-site audit (for Annex II QMS routes)
For full QMS assessment (Annex II), the UKAB conducts an on-site QMS audit at the manufacturer's facilities. The audit covers:
- QMS structure and documentation
- Design and development controls
- Production processes and controls
- Post-market surveillance arrangements
- Document and record management
The audit report includes further NCs and observations. Major NCs must be resolved before the QMS certificate is issued.
5. Design examination (for Class III / AIMD)
For Class III and AIMD devices, the UKAB performs a dedicated design examination of the design dossier. This may involve external expert review for clinical evidence components. A Design Examination Certificate is issued upon satisfactory completion.
6. Certification
Once all NCs are resolved, the UKAB issues:
- QMS Certificate (Annex II route)
- EC Type-Examination Certificate (Annex III route)
- Design Examination Certificate (Class III / AIMD only)
Certificates typically have a validity of 5 years, subject to annual surveillance audits.
7. UK Declaration of Conformity
The manufacturer issues a UK Declaration of Conformity — signed and dated — declaring that the device meets all applicable ERs, and referencing the UKAB certificate(s) where relevant.
8. UKCA mark
The UKCA mark is affixed to the device, accompanied by the UKAB's four-digit identification number (for certified devices).
Ongoing obligations after certification
Once certified, the manufacturer must:
- Maintain the QMS and notify the UKAB of significant changes
- Undergo annual surveillance audits by the UKAB
- Submit post-market surveillance data (PSUR) to the UKAB on request
- Notify the UKAB of design changes that may affect the certificate scope
- Renew the certificate before expiry (typically at the 5-year point, involving a full re-assessment)
Related pages
- Class I self-declaration pathway
- Class IIa · IIb · III — UKAB routes
- Full QMS assessment (Annex II)
- UK declaration of conformity
- UKCA marking requirements
- UK Approved Bodies
Official references
| Reference | Description |
|---|---|
| UK MDR 2002, Schedule 3 | Conformity assessment procedures (all annexes) |
| UK MDR 2002, Part II, Schedule 3 | AIMD conformity assessment |
| UK MDR 2002, Part III, Annexes IV–VII | IVD conformity assessment routes |
| MHRA: Conformity assessment for medical devices | MHRA guidance on route selection |
| gov.uk: UK Approved Bodies | Current list of designated UKABs |