What happened

Great Britain continues to operate under the former EU In Vitro Diagnostic (IVD) Directive, which was transposed into domestic law as the Medical Devices Regulations 2002 (MDR). Rather than adopting a risk-proportionate approach to classification, the MDR relies on a list-based system. Under this approach, specific high-risk tests are enumerated and subject to closer regulatory scrutiny, while the remaining IVDs are largely self-certified by the manufacturer. This framework is now widely regarded as outdated.

The EU moved to the risk-based In Vitro Diagnostic Regulation (IVDR) in 2022, but the UK did not follow suit. Post-Brexit, GB has pursued its own UK Conformity Assessed (UKCA) marking regime, though progress has stalled due to a lack of UK Approved Bodies and perpetual delays. CE-marked devices will continue to be accepted in GB until 2028 or 2030, depending on the device type. As a result, most manufacturers have continued to rely on their CE marks and deferred investment in UKCA compliance.

In July 2025, the UK government confirmed that it will legislate two significant pre-market reforms to the Medical Devices Regulations 2002: an international reliance framework enabling the Medicines and Healthcare products Regulatory Agency (MHRA) to accept regulatory approvals from comparable regulator countries (CRCs), and a new risk-based classification system for IVDs. For U.S. (and other international) pharmaceutical and MedTech companies, these changes create an immediate strategic decision window.

International reliance: a new route to the GB market for medical devices

Under the international reliance framework, the MHRA will rely on approvals or certificates issued by regulatory authorities in CRCs (namely the United States, Canada, and Australia), enabling medical devices to access the GB market more easily and to avoid full double certification. 

Notably, the original consultation proposals included the EU as a CRC. However, following strong consultee demand for indefinite recognition of CE-marked devices, the MHRA has deferred implementation of reliance routes for CE-marked products and will undertake further consultation. In the interim, CE-marked devices continue to be accepted on the GB market: until June 2028 for most devices, or until June 2030 for devices that comply with the MDR or IVDR.

Devices entering through international reliance will still need to meet GB-specific requirements, including English-language labeling and packaging, assignment of a unique device identifier, and appointment of a UK Responsible Person (see below). 

An additional development reinforces the UK–U.S. pharmaceutical partnership: In October 2025, the MHRA and U.S. Food and Drug Administration (FDA) announced a formal collaboration to align regulatory processes for medical devices and reduce duplication. Devices cleared under FDA frameworks (510(k), De Novo, or Premarket Approval) are expected to benefit from reliance routes active from 2027. In April 2026, the two agencies deepened this commitment, announcing strengthened cooperation on medical device regulation. This includes exploring mutual recognition mechanisms and streamlining approval processes.

The strategic fork for international medical device manufacturers

The reliance framework is potentially transformative for international pharmaceutical or MedTech companies in CRCs, but it does not eliminate the need for careful strategic planning. A U.S. manufacturer, for instance, that also requires EU market access may find that obtaining a CE mark remains the more efficient single path. This will depend on the outcome of the forthcoming consultation on indefinite CE-mark recognition in GB. The decision on market access strategy turns on product geography, commercial timeline, and the manufacturer’s appetite for maintaining parallel regulatory filings.

This decision needs to be made now. The legislation has not yet come into force, but transition periods, expected to be three years for medical devices and five years for IVDs, will begin running once it does. The preparation work is substantial enough that waiting for formal enactment will eat into that transition period unnecessarily. The consultation response should therefore be treated as a de facto starting gun because companies that defer assessment risk locking in a suboptimal regulatory posture.

IVD reclassification: a material shift

The MHRA will introduce a four-class system for IVDs (from Classes A to D) based on the level of risk to patients and public health. Under the new framework:

• Class A IVDs are self-declared.
• Class B requires self-declaration plus Quality Management System (QMS) certification.
• Class C requires conformity assessment by an approved body.
• Class D requires approved body assessment plus batch release testing and common specification requirements.

This is a significant departure from the current list-based system, under which only specifically enumerated high-risk tests (HIV, hepatitis, blood grouping) attracted rigorous scrutiny. Many IVD companies, including biotech companies with companion diagnostics, genomic testing platforms, and point-of-care products, will find their devices reclassified upward. This will trigger new conformity assessment obligations and, in some cases, approved body involvement for products that were previously self-certified. 

Companies should begin mapping their product portfolios against the new class structure before the legislation lands. Products moving into Classes C or D will need assessment by a UK Approved Body, and Approved Body capacity in the UK is already constrained. Manufacturers who identify affected products early can begin engaging Approved Bodies, building the necessary technical files, and upgrading quality management systems before demand spikes once the legislation comes into force.

Northern Ireland: a frequently overlooked complication

Northern Ireland remains subject to EU rules by virtue of the Windsor Framework, meaning CE marking is mandatory for devices sold there. A U.S. manufacturer entering the GB market through the international reliance route may find itself with a supply chain gap in Northern Ireland if it does not separately hold a CE mark. This is a significantly underappreciated issue in market access planning and merits early attention in any regulatory strategy.

The UK Responsible Person obligation

Any manufacturer not established in the UK must appoint a UK Responsible Person (UKRP). This is a UK-based entity that registers the device with the MHRA and takes on regulatory responsibility in Great Britain. For the United States and other non-UK manufacturers, this is a live compliance obligation under the current regime and raises practical structuring questions: whether to appoint a dedicated UKRP, use a distributor in that role, or establish a UK entity. The UKRP requirement is not affected by the reforms and will persist under the new framework.

What to do now

The regulatory landscape for medical devices in Great Britain is entering a defined period of transition. Manufacturers with existing or planned UK market presence should consider taking the following steps:

• Assess your GB market access strategy. Determine whether the international reliance route, CE marking, or both best serve your product portfolio and commercial objectives across the UK and EU.
• Map your IVD portfolio against the new classification framework. Identify products likely to be reclassified upward and plan for new conformity assessment and QMS obligations.
• Evaluate your Northern Ireland position. Confirm whether your regulatory strategy provides uninterrupted supply chain coverage across both GB and Northern Ireland.
• Review your UK Responsible Person arrangements. Ensure your UKRP appointment is current, appropriately structured, and aligned with your broader distribution and commercial arrangements.

Client Alert 2026-107