What Martyn's Law Means for Your Building's Security

After years of campaigning, Martyn's Law, formally the Terrorism (Protection of Premises) Act 2025, received Royal Assent on 3 April 2025. It is named in memory of Martyn Hett, one of the 22 people killed in the 2017 Manchester Arena attack and introduces a legal duty to consider how premises and events would respond to a terrorist attack.

The Act is not yet in force. The Government has committed to an implementation period of at least 24 months so that organisations have time to prepare and a regulator (the Security Industry Authority) can be established, which means the duties are expected to take effect from around 2027. That lead-in is exactly the window in which sensible preparation pays off.

Who is in scope?

The duty applies to publicly accessible premises with a capacity of 200 or more people. The categories named in the Act are broad, they include retail, hospitality, entertainment and leisure venues, places of worship, healthcare and education sites, sports grounds, visitor attractions and other community and event spaces. If members of the public can access your premises and you reach that headcount, it is worth checking where you stand.

The two tiers

• Standard tier (200-799 capacity). The focus here is on simple, low-cost procedures: having a plan for what staff would do in an attack, evacuation, moving people to safety (invacuation), lockdown and clear communication and making sure people are trained on it.
• Enhanced tier (800+ capacity). Larger premises must additionally assess their vulnerability and, where appropriate, put in place measures to reduce the risk and the potential impact of an attack and document them.

Where security systems fit in

Much of the Standard tier is procedural rather than about hardware and that is deliberate. But in practice, the physical security already in your building is what makes those procedures workable. The measures that most often underpin a credible plan include:

• Lockdown-capable access control, the ability to secure or release doors, zones or a whole building quickly from a single point.
• CCTV and monitoring, situational awareness before, during and after an incident, ideally with a monitored control room.
• Clear communication, intercom, public address and entry systems that let you direct people calmly.
• Visitor and contractor management, knowing who is in the building and being able to account for them.

For Enhanced-tier sites, integration is what turns these from separate boxes into a coherent response: access control, CCTV, intercom and visitor systems working together, with documented procedures behind them.

What to do now

There is no need to rush into wholesale change, but the implementation window is the right time to take stock. Confirm which tier your premises are likely to fall into, review your existing systems against the kind of response the Act envisages and identify the gaps. Where upgrades make sense, extending lockdown capability, adding monitored CCTV, improving communication, they are far less disruptive done deliberately now than in a hurry later.

Sources & further reading

• The Terrorism (Protection of Premises) Act 2025, GOV.UK
• Martyn's Law overview, ProtectUK (Counter Terrorism Policing)

This article is general information, not legal advice. For the definitive requirements that apply to your premises, refer to the official Government and ProtectUK guidance above.