The compliance picture under Martyn's Law is now clear enough to act on. The Terrorism (Protection of Premises) Act 2025, known as Martyn's Law, has its Home Office statutory guidance published as of April 2026, and it sets out how premises decide whether they are in scope.
Scope turns on capacity. The standard tier covers qualifying premises where 200 to 799 people may reasonably be present at once; the enhanced tier covers premises and events expecting 800 or more. The Security Industry Authority is named as the regulator.
The duties are not live yet. The guidance confirms at least 24 months from Royal Assent, which was 3 April 2025, before the substantive requirements commence, putting enforcement into 2027, and the SIA's own operational detail on how it will inspect, advise and penalise is still being finalised.
The gap between guidance published and duties enforced is the planning window, not a reason to wait. Standard-tier premises will need to have worked through evacuation, invacuation, lockdown and communication procedures; enhanced-tier sites face documented risk assessments and a named responsible person.
Operator implication: if you run security for venues, events or estates, map which sites fall into which tier now and build the procedures while there is time to test them. Operators who can walk clients through scoping and the reasonably-practicable measures have a service to sell before the deadline forces it. Waiting for the SIA to switch enforcement on is the expensive way to do this.
