Clifford Chance

Martyn's law enacted to require buildings and events to mitigate terrorism risk

21 May 2025

Nearly eight years on from the Manchester Arena and London Bridge terror attacks, the Terrorism (Protection of Premises) Act 2025 (the “Act”) has been passed to enhance the protective security and organisational preparedness of premises across the UK against terrorist activities. The Act is otherwise known as Martyn’s law after Martyn Hett, one of the people tragically killed in the Manchester Arena attack. The Act mandates that those responsible for certain premises take steps to mitigate the risk of physical harm to individuals in the event of a terrorist attack. Additionally, those responsible for certain larger premises and events are required to take steps to reduce the vulnerability of the premises to terrorist attacks. The main duties are expected to come into effect around early 2027.

The key provisions of the Act introduce public protection requirements based on a tiered approach that recognises that premises and events with larger numbers of people (Enhanced Duty Premises and Qualifying Events, respectively) may face greater consequences from a terrorist attack. The Act gives relevant powers to the Security Industry Authority (the “SIA”) as the regulator to enforce these provisions. This Briefing takes a look at the provisions as they will apply in England & Wales.

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