The Terrorism (Protection of Premises) Act 2025, also known as Martyn’s Law, received Royal Assent on Thursday 3 April 2025.  

This Act delivers the Government’s manifesto commitment to strengthen the security of public premises and events. 

The Government would like to pay tribute to Figen Murray, mother of Martyn Hett, who was killed in the Manchester Arena attack.  Her campaigning has been crucial in driving this Act forward.   

The Government intends for there to be an implementation period of at least 24 months before the Act comes into force. This will allow the SIA’s new function to be established, whilst ensuring those responsible for premises and events in scope have sufficient time to understand their new obligations. This will enable them to plan and prepare appropriately. 

Why has the Government introduced Martyn’s Law? 

Since March 2017, Counter Terrorism Policing assesses that there have been 15 domestic terror attacks in the UK (not including Northern Ireland-related terrorism), and security services and law enforcement have together disrupted 43 late-stage plots. 

The threat picture is complex, evolving and enduring, with terrorists choosing to attack a broad range of locations. It is not possible to predict where in the UK an attack might happen, or the type of premises or event that could be impacted – either directly as the target of an attack, or indirectly by being located near to the target of an attack.   

Engagement with business indicates that preparedness and protective security in the counter-terrorism space often falls behind areas where there are long-established legal requirements, such as health and safety. The police, security services, and other partners continue to do all they can to combat the terror threat; and many businesses and organisations already do excellent work to improve their security and preparedness. However, the absence of legislative requirements means there is no consistency of consideration or of outcomes achieved. 

That is what this Act seeks to address.  

What does Martyn’s Law do?  

The Terrorism (Protection of Premises) Act 2025, also commonly referred to as Martyn’s Law, will improve protective security and organisational preparedness across the UK by requiring that those responsible for certain premises and events consider how they would respond to a terrorist attack. In addition to this, at certain larger premises and events, appropriate steps to reduce vulnerability to terrorist attacks must also be considered. Through the Act, qualifying premises and events should be better prepared and protected, ready to respond in the event of a terrorist attack.  

Whilst those that fall within scope of the Act may wish to begin considering the requirements, they should note that guidance will be published in due course. This guidance will assist in understanding the requirements set out in the legislation. The guidance is being designed to be easy to follow, needing neither particular expertise nor the use of third-party products or services. 

To support enforcement of the regime, a regulator will be established through a new function of the Security Industry Authority (SIA), which will support, advise and guide those responsible for premises and events in meeting the requirements of this legislation. 

Who will be in scope? 

Premises that satisfy the following four criteria fall within scope of the Act: 

1. There is at least one building (or the premises are in a building); 

2. The premises are wholly or mainly used for one or more of the uses specified at Schedule 1 to the Act, e.g. a restaurant or a shop; 

3. It is reasonable to expect that at least 200 individuals may be present at least occasionally; and 

4. The premises are not excluded under Schedule 2 to the Act 

If 800 or more individuals may be expected, the premises will be an enhanced duty premises unless the Act says otherwise. 

An event that satisfies the following criteria fall within scope of the Act: 

1. It will take place at premises within section 3(1)(a) of the Act, including land without buildings, that are not enhanced duty premises (or part of enhanced duty premises); 

2. The relevant premises are accessible to members of the public for the purpose of the event; 

3. It is reasonable to expect that there will be at least 800 individuals present for the event at once at some point during it;  

5. There will be measures to check entry conditions are met, such as a ticket checks; and 
6. The event is not excluded under Schedule 2 to the Act.