Martyn's Law comes into force in 2027. This is what proportionate looks like.
The Terrorism (Protection of Premises) Act 2025 received Royal Assent in April 2025. Every UK venue with a capacity of 200 or more people is now in scope. This page explains what the law requires, what proportionate safety measures mean in practice, and how AI behaviour detection meets the standard.
Two months free. No hardware. No commitment beyond the conversation.
01 / The Law
Background
The Terrorism (Protection of Premises) Act 2025.
What it says. What it means for you.
Martyn's Law is named after Martyn Hett, one of the 22 people killed in the Manchester Arena attack in 2017. The Act received Royal Assent in April 2025 and requires venues across the UK to take steps to protect the public from terrorist threats.
Enforcement begins in April 2027. The 24-month implementation period gives venues time to assess their obligations and put measures in place. The window is not an extension on urgency. It's the lead time required to do this properly.
Are You in Scope?
If your venue has a capacity of 200 or more, you are in scope.
The Act covers all venues and events with a qualifying capacity. Qualifying premises include:
- Bars, nightclubs, pubs and licensed entertainment venues
- Hotels with event or conference facilities
- Theatres, music venues and arenas
- Restaurants and dining venues with 200+ seated capacity
- Shopping centres and retail complexes
- Exhibition venues, stadiums and sports grounds
- Places of worship above the qualifying threshold
Enhanced Tier: 800+ capacity
If your venue is Enhanced Tier (800+), you have the additional obligation to demonstrate proportionate physical controls. Your existing CCTV is not sufficient on its own.
Two tiers. Different obligations.
Standard Tier venues must develop procedures for their staff to follow in a terrorist attack. This includes procedural measures: evacuation plans, lockdown procedures, communication protocols.
Enhanced Tier venues must go further. In addition to the procedural obligations, Enhanced Tier venues must implement physical protective measures, appoint a designated responsible person, conduct documented vulnerability assessments, and be able to demonstrate proportionate safety controls to the Security Industry Authority.
AI behaviour detection is a physical protective measure. It is precisely the kind of active, documented, technology-led intervention that satisfies ‘proportionate’ under the enhanced tier requirements.
Proportionate Safety Measures
"We had cameras" won't satisfy the SIA.
Active AI monitoring will.
The Act requires Enhanced Tier venues to implement ‘reasonably practicable physical measures’ to protect people from terrorist attack. Reasonably practicable is a legal standard. It means you've done everything you could do, given the resources and technology available, to reduce the risk.
CCTV records. That is a passive measure. It documents what happened.
Archangel detects and alerts before an incident escalates. That is an active measure. It creates the possibility of intervention. It also creates a documented record of active monitoring: a log of alerts, detection events and operator responses that demonstrates, to the SIA and to any subsequent investigation, that the venue was operating with active safety controls in place.
That documentation is what proportionate looks like when it is tested.
Archangel and Martyn's Law
What Archangel adds to your existing venue safety infrastructure.
Active detection across your existing camera network.
No new hardware. No infrastructure replacement. Your cameras stay. The detection layer goes live on top of them.
Real-time alerts before situations escalate.
Your team is notified with a clip and context before an incident develops. That response capability is what distinguishes active monitoring from passive recording.
Documented detection log.
Every alert, every confirmed detection, every operator response is logged. That log is your evidence of active safety controls when the SIA conducts its assessment.
Crowd and access anomaly detection.
The specific behavioural patterns that precede a major incident — unusual crowd gathering, perimeter breach, unattended items in public areas — are precisely what Archangel's detection layers are built to find.
Threat escalation before the incident.
The window between a detected anomaly and an escalating incident is where intervention is possible. Archangel creates that window.
The Commercial Reality of Compliance
Capital expenditure on new camera systems is not a requirement for Martyn's Law compliance.
Most venues of 800+ capacity already have an IP camera network in place. Martyn's Law does not require you to replace it. What the Enhanced Tier standard requires is that your monitoring is active, not passive. That distinction is the difference between your existing CCTV and Archangel running on it.
Archangel's AI detection layer operates on your existing camera infrastructure. No new hardware. No capital expenditure on replacement systems. No extended installation contract. The proportionate response to Martyn's Law is not a building project. It is adding intelligence to the infrastructure you already paid for.
For venue operators making compliance decisions under budget pressure, this matters. The route to Enhanced Tier compliance does not require a large upfront spend. It requires the right software layer, deployed on what you already have.
April 2025: Royal Assent.
April 2027: Enforcement begins.
The 24-month implementation window is designed for venues to assess their obligations, appoint a responsible person, conduct vulnerability assessments, and put their physical measures in place.
For Enhanced Tier venues, this means commissioning and deploying technology that satisfies the proportionate standard. Archangel connects to existing IP camera infrastructure. Deployment is not a 6-month project. But it requires a discovery call, an environment assessment, and a deployment schedule. Starting in Q4 2026 is not starting early enough.
Start the conversation now.
Understand what Martyn's Law means for your specific venue.
Book a discovery call with our team. We'll assess your venue tier, your existing camera infrastructure, and what active AI monitoring looks like for your environment. Two months free means you can start before enforcement begins without committing to long-term costs up front.
Two months free. No hardware. No commitment beyond the conversation.