Who Holds the Duty? Martyn's Law and the Principal Use of Premises
Protective Security | Emerging Risks Global
Why the question of who holds the duty must be settled before the duties begin
The Question Behind the Duties
Martyn's Law places duties on people, not on buildings. Before anyone can plan procedures or measures, they need to know who holds the duty. For a single-use venue the answer is usually plain. For a hotel with a restaurant, a leisure complex with several operators or a building that hosts public events alongside its main purpose, it is not.
The Terrorism (Protection of Premises) Act 2025 received Royal Assent in April 2025. Its duties are not yet in force. The Government intends an implementation period of at least 24 months, and there is no requirement to comply until the duties come into force (ProtectUK). Commentary on the latest Home Office guidance reports that the substantive duties are not expected to commence until spring 2027 (National Law Review). No commencement date has been confirmed.
What Changed on 15 October
One part of the framework is now law. The Terrorism (Protection of Premises) (Principal Use of Premises) Regulations 2026 came into force on 15 October 2026 (legislation.gov.uk). The Home Office published guidance on the principal use of premises on 10 September 2026 (GOV.UK).
The Regulations apply where premises have two or more of the uses listed in Schedule 1 of the Act. In those cases, the principal use is the use that relates most closely to the purpose and nature of the premises. The principal use then identifies the responsible person.
How Principal Use Is Decided
The Regulations set out a two-stage test. The first stage looks at four factors:
whether the premises were built or modified for a particular use
whether they continue to be used for that use
their physical characteristics
whether the local authority treats them as having a particular use
If that does not settle the matter, all relevant circumstances are considered. These include whether each use occupies the whole premises or only part, the proportion each use occupies, how long each use runs over a relevant period and whether one use is carried on to support another.
Control, Not Labels
The practical message is that responsibility follows control. Ownership, branding and holding a premises licence do not by themselves decide who the responsible person is (National Law Review). In a leased pub, the tenant who controls the use may hold the duty rather than the brewery. Separate qualifying premises are not merged simply because they share a building or an estate.
Contracts still matter. Leases and management agreements can allocate tasks and costs. They do not replace the Act's rules on who is legally responsible.
What This Means Now
Because the duties are not yet in force, this is a period for clarity rather than compliance. Several questions are worth answering early:
Which premises have more than one Schedule 1 use?
What is the likely principal use of each, and what evidence supports that view?
Which legal entity controls that use day to day?
Do leases and management agreements reflect that position?
When will the assessment be reviewed after refurbishment, a change of use or a change of operator?
Answering these questions now avoids a rushed argument about responsibility when the duties begin. It also gives the right person time to understand what their tier will ask of them. At the standard tier, for premises where 200 to 799 people may be present, that means notifying the Security Industry Authority and having appropriate public protection procedures. There is no requirement for physical security measures at this tier. At the enhanced tier, for 800 or more people, it also means appropriate measures to reduce vulnerability and a document setting out procedures and measures for the regulator (ProtectUK).
How ERG Can Help
SecurePrem, ERG's built-environment audit and design tool, looks at premises as they are actually used. That is where principal use questions are answered. ERG's readiness work helps organisations understand where they stand before the duties begin. It is not legal advice and does not certify compliance.
To discuss a site or a portfolio, contact information@emergingrisksglobal.com or visit ERG's Martyn's Law page.
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