What is Martyn's Law?
Martyn's Law is the Terrorism (Protection of Premises) Act 2025. It requires those responsible for certain premises and events to take steps to be better prepared for, and to reduce the harm from, a terrorist attack. It received Royal Assent on 3 April 2025 and is expected to come into force around spring 2027, though the exact date is not yet fixed (as at 12 July 2026). Premises with 200 to 799 people expected at the same time sit in the standard tier; 800 or more sit in the enhanced tier. The Security Industry Authority (SIA) is the regulator.
Where the name comes from
Martyn's Law is named after Martyn Hett, one of the 22 people killed in the Manchester Arena attack in May 2017. His mother, Figen Murray, campaigned for a legal duty on venues to prepare for attacks. The result is the Terrorism (Protection of Premises) Act 2025, popularly known as Martyn's Law.
What the law actually asks you to do
The Act does not ask most operators to buy expensive equipment or rebuild their premises. At its core it asks the people responsible for a venue to think ahead about what they would do in an attack, and to have appropriate procedures ready. The level of what is required depends on how many people your premises is expected to hold.
The two tiers
Scope and obligations are set by the greatest number of individuals who may reasonably be expected to be present at the same time, from time to time, for a qualifying (Schedule 1) use:
- Standard tier: 200 to 799 people. Notify the SIA, and have appropriate public protection procedures in place across four areas: evacuation, invacuation, lockdown and communication. No building works or equipment are required, and no formal written document is legally required at this tier.
- Enhanced tier: 800 or more people. Everything the standard tier requires, plus public protection measures across monitoring, movement, physical safety and security, and information security, a mandatory tailored document kept up to date, and, if the responsible person is an organisation, a designated senior individual.
Under 200 people, a premises is out of scope on capacity.
Qualifying events
Separately from premises, an event qualifies where 800 or more people may reasonably be expected at the same time, the premises are not otherwise qualifying premises, the public has access, and access is controlled by payment, ticket, membership, invitation or express permission. Qualifying events sit in the enhanced tier.
Staff count. When you assess your number, include workers and volunteers, not just the public. The test is the greatest number reasonably expected at the same time, and recurring seasonal or day-of-week peaks count. See our guide on how to count your capacity.
Who is responsible
The responsible person is the individual, organisation or company with control of the premises for the purpose of its Schedule 1 use, or, for an event, the person with control of the premises for the event. Where more than one person has control, responsibility can be shared and each must play its part.
The regulator and the penalties
The Security Industry Authority (SIA) is the UK-wide regulator, operating a new regulatory function for Martyn's Law. Its enforcement tools include compliance notices, restriction notices and penalty notices. Once the law is in force, the maximum monetary penalty is £10,000 at standard tier, and £18 million or 5% of qualifying worldwide revenue, whichever is greater, at enhanced tier and for events. There are also daily penalties for continuing non-compliance and criminal offences for providing false information or obstructing an inspector. The SIA's detailed section 12 enforcement guidance is still in development.
When it comes into force
The commencement date is not yet fixed in law. The Home Office has committed to an implementation period of at least 24 months from Royal Assent on 3 April 2025, and commencement is expected around spring 2027, with the earliest possible being April 2027. The exact date will be set by regulations and confirmed to Parliament. Until then, the duties are not yet legal obligations, but the runway is deliberately there so you can prepare.
Frequently asked questions
Is Martyn's Law in force yet?
Not yet. The Act received Royal Assent on 3 April 2025, but commencement is set separately by regulations. Commencement is expected around spring 2027. Treat it as expected, not fixed, as at 12 July 2026.
Who does Martyn's Law apply to?
Those responsible for qualifying premises used for a Schedule 1 purpose with 200 or more people expected at the same time, and for qualifying events of 800 or more with controlled access.
Who enforces Martyn's Law?
The Security Industry Authority (SIA), the UK-wide regulator. Its section 12 enforcement guidance is still in development as at 12 July 2026.
Sources
- Terrorism (Protection of Premises) Act 2025 The full text of the Act, ukpga/2025/10. legislation.gov.uk/ukpga/2025/10/enacted
- Home Office statutory guidance The published guidance on the duties, tiers and assessment of numbers. gov.uk statutory guidance
- Home Office media factsheet (3 April 2025) Royal Assent, the implementation period and the expected timeline. homeofficemedia.blog.gov.uk
Content current as at 12 July 2026. The commencement date and guidance can change; re-check the primary source before acting on anything time-sensitive.
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