Healthcare & Social Care Product compliance and marking

Classify your medical device for the GB market

How to classify your medical device under the UK Medical Devices Regulations 2002. Covers Class I through III for general devices, active implantable devices, IVDs (current Annex system and future Class A-D), and Software as a Medical Device.

UK-wide
Guide summary

You must classify your medical device before selling it in Great Britain. The class depends on risk, use, and how it interacts with the body. Higher-risk devices need approval from a UK Approved Body. Check the rules in Annex IX of the Medical Devices Regulations 2002.

  • Classify your device by risk, use, and body contact
  • Use Annex IX rules to find your device class
  • Class I (low risk) devices need self-certification
  • Class Is and Im need UK Approved Body checks
  • Class IIa and IIb require UK Approved Body assessment
  • Class III and AIMDs need full UK Approved Body approval
  • IVDs currently use annexes but will move to classes A-D
  • AI and software devices must be registered with MHRA
  • CE marked devices are accepted until June 2028 or 2030
  • Wrong classification risks penalties up to 6 months jail
On this page
UK-wide

Related guides in General Compliance

Medical device compliance checklist

Verification checklist for medical device manufacturers and UK Responsible Persons. Covers device classification, conformity assessment, technical documentation, UKCA/CE …

Before you can place a medical device on the Great Britain market, you must determine its risk classification. The classification determines which conformity assessment route applies and whether you need a UK Approved Body to certify your device.

Classification rules are in Annex IX of the retained EU Medical Devices Directive (93/42/EEC), applied through the Medical Devices Regulations 2002. Classification depends on the device's intended purpose, invasiveness, duration of body contact, and whether it is active.

Classification by conformity assessment route

Your device class determines how much regulatory scrutiny it receives:

  • Class I (non-sterile, non-measuring): Self-certification. You draw up the Declaration of Conformity yourself. No UK Approved Body needed.
  • Class Is (sterile) and Im (measuring): Self-certification for the device itself, but a UK Approved Body must assess the sterility or metrological aspects.
  • Class IIa: UK Approved Body assessment required. Options include product verification, quality system audit, or type-examination.
  • Class IIb: UK Approved Body full assessment required. Type-examination or full quality assurance system audit.
  • Class III: Most rigorous route. UK Approved Body must conduct full design examination and quality system assessment, including clinical data review.

Active implantable medical devices

Active implantable medical devices (AIMDs) are regulated under Part III of the UK MDR 2002. These are devices intended to be totally or partially introduced into the human body and remain after the procedure. Examples include cardiac pacemakers, implantable defibrillators, cochlear implants, and neurostimulators.

All AIMDs require UK Approved Body full assessment. Only BSI Assurance UK Ltd is currently designated for Part III (active implantable devices).

In vitro diagnostic devices (IVDs)

IVDs are regulated under Part IV of the UK MDR 2002. Under the current system, IVDs are classified by annexes rather than risk-based classes:

  • Annex II List A: High-risk IVDs such as blood grouping and HIV testing reagents. Require UK Approved Body assessment.
  • Annex II List B: Moderate-risk IVDs such as pregnancy and fertility tests. Require UK Approved Body assessment.
  • Self-testing devices: Devices intended for lay persons. Require UK Approved Body assessment for suitability for self-testing.
  • General IVDs: All other IVDs. Self-certification by manufacturer.

Future IVD classification: MHRA will introduce a new risk-based system with four classes (A to D), aligning with international standards. Class A (lowest risk) will allow self-declaration. Class B will require QMS certification. Classes C and D will require UK Approved Body assessment. This change is expected via a statutory instrument in 2026.

Getting classification advice

If you are unsure how to classify your device, MHRA offers a Devices Regulatory Advice Meeting service. You can request a one-hour meeting to discuss classification, conformity assessment, or regulatory strategy. This is a fee-based service.

For borderline cases, MHRA may issue a formal classification decision on request.

Classification guidance