October 19, 2026

Martyn's Law Explained: What It Is, Who It Applies To and When It Starts

Martyn's Law is the UK's new terrorism preparedness legislation for publicly accessible venues and events. Formally called the Terrorism (Protection of Premises) Act 2025, it requires organisations responsible for qualifying premises to think about the threat of terrorism and put reasonably practicable procedures in place to reduce harm if an attack happens.

Written by

Meelik Samel

Martyn's Law Explained: What It Is, Who It Applies To and When It Starts

This page is your starting point. It covers what Martyn's Law is, why it exists, who it applies to, what it requires and when to expect it to take effect. Where you need more depth, we link to a dedicated guide.

What is Martyn's Law?

In short, Martyn's Law is about preparedness. Rather than prescribing the same security measures for every site, it asks those in control of a premises or event to understand their risk, plan proportionately and make sure staff know how to respond. For many organisations that means strengthening existing procedures, not buying expensive infrastructure.

Why is it called Martyn's Law?

The law is named after Martyn Hett, one of the 22 people killed in the Manchester Arena attack on 22 May 2017. His mother, Figen Murray OBE, campaigned for greater preparedness at public venues. Together with recommendations from the Manchester Arena Inquiry, her work led to the Act, which received Royal Assent on 3 April 2025.

Is Martyn's Law the same as the Protect Duty?

Yes, in effect. The proposals were originally known as the "Protect Duty" and were renamed Martyn's Law in tribute to Martyn. You'll still see both names used, and searches for "protect duty" are usually about this same legislation. The law sits within the "Protect" and "Prepare" strands of the government's CONTEST counter-terrorism strategy, which is also the closest thing to an official tagline: Protect and Prepare.

Who does Martyn's Law apply to?

It applies to people responsible for qualifying premises and certain events where 200 or more people may reasonably be expected to be present at the same time. That includes:

Retail and shopping centres
Hospitality venues
Entertainment and leisure venues
Visitor attractions
Places of worship
Schools, colleges and universities
Healthcare settings
Public buildings
Certain temporary events

Premises below 200 capacity are generally out of scope, as are most private workplaces that aren't publicly accessible and transport premises already covered by other security legislation. The Act applies across the whole UK, including Scotland, so there is no separate "Martyn's Law Scotland" to wait for.

The two tiers at a glance

Standard Duty (200 to 799 people): practical procedures for evacuation, invacuation, lockdown and communication.
Enhanced Duty (800+ people): everything in the Standard Duty, plus a designated senior individual, a formal compliance document and the ability to demonstrate compliance to the regulator.

Full detail is in our guide to Standard vs Enhanced Tier requirements.

When does Martyn's Law come into effect?

The government committed to an implementation period of at least 24 months from Royal Assent, so duties cannot be enforced before April 2027. Government and the regulator expect the Act to come into force in spring 2027, but the Home Office will confirm the exact commencement date via Parliament. Treat spring 2027 as the date to be ready by, not the date to start planning, and check GOV.UK for the confirmed date. Our Martyn's Law timeline and updates page tracks every key date.

Who enforces it?

The Security Industry Authority (SIA) is the regulator. It has said it intends to take a "support first" approach, and it ran a public consultation on its draft statutory guidance in 2026. Powers include compliance notices, restriction notices and financial penalties. The maximum is £10,000 for Standard Duty and £18 million or 5% of global revenue for Enhanced Duty, with daily penalties for continued non-compliance. Read more in the SIA's guidance on its role as regulator.