The recent publication of regulations under Martyn’s Law provides welcome clarity for operators, landlords and occupiers of multi-use premises. One of the key practical questions under the new regime has been identifying who is responsible for compliance where a building serves more than one purpose. The latest regulations seek to answer that question.
Martyn’s Law: How to determine the principal use of multi-use premises
The government has taken another step towards implementation of the Terrorism (Protection of Premises) Act 2025 (Martyn’s Law) by laying the Terrorism (Protection of Premises) (Principal Use of Premises) Regulations 2026 before Parliament.
The Regulations address an important issue for owners and operators of multi-use premises: how to identify the 'principal use' of a premises where it falls within more than one of the specified uses listed in the Act.
Why does principal use matter?
Under Martyn’s Law, responsibility for compliance rests with the responsible person. For premises with multiple qualifying uses, the responsible person will be the individual or organisation that controls the premises in connection with its principal use.
Determining principal use is therefore not simply an academic exercise. It can determine who bears responsibility for meeting the Act’s requirements and ensuring appropriate security measures are in place.
The new test
The Regulations provide that principal use should be identified by considering which use is most closely connected to the purpose and nature of the premises.
A range of factors may be relevant, including whether the building was originally designed, constructed or subsequently modified for a particular use.
Where the answer is not obvious, the assessment must be carried out on a case-by-case basis having regard to all relevant circumstances. Additional considerations may include:
- the proportion of the premises occupied by each use;
- the amount of time the premises are used for each activity; and
- other factors relevant to the overall character and operation of the premises.
Practical examples
The accompanying government guidance provides useful illustrations.
One example considers a sports stadium that hosts regular sporting events while also accommodating meetings and visitor tours. Although the stadium has multiple qualifying uses, its primary purpose and character are clearly sporting in nature. As a result, its principal use is as a sports ground, and the person controlling the premises for that purpose will be the responsible person under the Act.
The guidance emphasises that the focus should remain on the overall purpose and nature of the premises rather than simply counting activities that take place within it.
Additional points to note
The guidance also makes clear that:
- a principal use assessment will not usually be required where different uses sit within separate qualifying premises, such as individual units within a shopping centre;
- assessments should be revisited where circumstances change, for example following refurbishment or a significant change in how the premises are used; and
- organisations should keep a written record of any principal use determination and the reasons supporting it.
How we can help
Although Martyn’s Law is not expected to come into force before April 2027, organisations that own, occupy or manage premises open to the public should continue to monitor developments and begin considering how the legislation may affect their property portfolios and operational responsibilities.
These latest Regulations provide greater certainty for multi-use premises and offer a practical framework for determining responsibility. However, for many complex sites, applying the principal use test is likely to require careful analysis of both the physical characteristics of the premises and the way they are operated in practice.
If you would like advice on Martyn's Law and what it may mean for your organisation, please contact Dawn MacPherson, or another member of Anderson Strathern's Commercial Property team.