Counter-Terrorism Security

The Terrorism (Protection of Premises) Act, also known as Martyn's Law, received Royal Assent on 3 April 2025. The Act has been designed to bolster the UK's preparedness for – and protection from – terrorism.

Those responsible for certain premises or events will be required to consider the terrorist risk and how they would respond to an attack. There will be an implementation period of at least 24 months before the Act comes into force, and this page considers the likely implications for the heritage sector.

Background

Following a campaign by Figen Murray, mother of Martyn Hett, who was killed in the Manchester Arena attack, the Terrorism (Protection of Premises) Bill achieved Royal Assent on 3 April 2025. Also known as Martyn's Law, it requires qualifying premises and events to reduce the risk of harm from a terrorist attack by implementing public protection procedures and measures.

For a premises to be in scope, it must be reasonably expected to have 200 or more individuals on the premises at the same time. For an event to be in scope, it must be reasonable to expect that 800 or more individuals will be present at any one time.

Smaller premises (200 to 799 individuals) within the standard tier are required to put in place simple procedures to reduce the risk of physical harm to individuals who may be present. Those responsible for larger premises and events (800+) in the enhanced tier are required to do more by having physical security measures designed to reduce the site's vulnerability to an attack.

Whilst those that fall within the scope of the Act may wish to begin considering the requirements, they should note that Home Office guidance will be published in due course. The government intends for an implementation period of at least 24 months before the Act comes into force. This will allow a new regulatory function to be established within the Security Industry Authority (SIA), which will seek to support, advise and guide those responsible for premises and events in meeting the requirements of this legislation. It will also ensure those responsible for premises and events in scope have sufficient time to understand their new obligations and enable them to plan and prepare appropriately.

Considerations for the heritage sector

Historic England aims to support the implementation of Martyn's Law across the heritage sector, to help enhance the resilience of premises and events at sites encompassing heritage assets, and to improve the safety of staff, volunteers, and members of the public.

We are working with the heritage sector, security partners, and government to understand the challenges qualifying sites may face in complying with the Act. This page will be updated with further information for the heritage sector as advice and guidance are developed.

Further reading

• More information on the Terrorism (Protection of Premises) Act
• Factsheets with information on qualifying premises and events, and the procedures and measures required
• Counter-terrorism security guidance and advice from ProtectUK and National Protective Security Authority
• Historic England's emergency planning advice
• Historic England's heritage crime advice