Martyn’s Law Explained: What It Means for Your Premises
If you run a venue, event space, retail site or public-facing building, you’ve probably heard the term “Martyn’s Law” mentioned in the last year or two — but it isn’t always clear what it actually requires, or whether it applies to you at all. Below, we explain the law in plain terms and introduce a free tool that gives you an instant, guided answer.
What is Martyn’s Law?
Martyn’s Law is the popular name for the Terrorism (Protection of Premises) Act 2025. It received Royal Assent on 3 April 2025 and is named in memory of Martyn Hett, one of the twenty-two people killed in the 2017 Manchester Arena attack.
The Act introduces a new legal duty for certain premises and events to prepare for, and respond to, the possibility of a terrorist attack. It doesn’t ask organisations to predict whether an attack will happen — it’s built on the principle that one could happen anywhere, and asks businesses to have sensible, proportionate plans in place regardless.
The Home Office published statutory guidance in April 2026 to help organisations understand exactly how the Act applies to them, and enforcement is expected to follow an implementation period running into 2027 — so now is the time to understand where your organisation stands, not once inspections begin.
Who does it apply to?
Martyn’s Law applies to premises that are used, wholly or mainly, for a qualifying public-facing activity — retail, hospitality, leisure and entertainment, sports grounds, visitor attractions, places of worship, and similar public-facing uses — and where the maximum number of people reasonably expected on-site at the same time meets a capacity threshold.
There are two tiers:
Tier | Capacity | What’s required |
|---|---|---|
Enhanced Tier | 800+ people | Everything in Standard Tier, plus a formal, documented terrorism risk assessment, reasonably practicable physical security measures, and a named Designated Senior Individual accountable for compliance |
Standard Tier | 200–799 people | Procedural readiness: evacuation, invacuation, lockdown and communication plans, plus staff awareness |
Premises below 200 people, or those not used for a qualifying public activity, are generally out of scope — though mixed-use sites and multi-tenant buildings can be genuine grey areas worth checking properly.
Why it matters now
A few things make this a live issue for business owners in 2026, not a distant compliance date to file away:
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Statutory guidance is out. The Home Office guidance published in April 2026 gives clear decision trees for establishing whether your premises is in scope — the ambiguity is narrowing.
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Enforcement is coming. The Security Industry Authority is building out its inspection capability ahead of the law taking effect.
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Reputational and liability exposure. Beyond the legal duty, being unable to demonstrate basic preparedness is a genuine risk to staff, visitors and the organisation’s standing.
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It’s cheaper to plan than to retrofit. Standard Tier requirements are largely procedural and low-cost to put in place early. Leaving it late tends to mean rushed, more expensive fixes.
How our Martyn’s Law Checker works
We’ve built a free, 60-second tool to give you an instant first read on where your premises stands. It asks two straightforward questions:
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What’s the maximum number of people reasonably expected on-site at once?
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Is the premises used, wholly or mainly, for a public-facing activity?
Based on your answers, the checker tells you whether you’re likely out of scope, likely to fall under Standard Tier, or likely to fall under Enhanced Tier — and explains, in plain terms, what that tier would mean for you in practice. If your situation is genuinely borderline (mixed use, multiple tenants, seasonal capacity changes), the tool flags this and points you towards a proper site review rather than guessing.
It’s designed to be a starting point, not a final legal determination — final scope depends on your specific premises and the statutory guidance in full, which is why every result includes the option to book a free assessment with our team.
What to do next
Whether the checker tells you you’re in scope or not, a few sensible next steps apply to almost every organisation:
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Document your current capacity and how it’s calculated.
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Review whether your existing evacuation and lockdown procedures would hold up to scrutiny.
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If you’re in Enhanced Tier territory, start thinking now about who would hold the Designated Senior Individual role.
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Get a professional opinion before, not after, the enforcement window opens.
WOSS:UK works with venues, retailers, construction sites, event organisers and corporate premises across the North West to assess Martyn’s Law exposure and put practical, proportionate measures in place. If you’d rather skip straight to a proper site review, get in touch with our team.
This article is for general guidance only and does not constitute legal advice. Organisations should refer to the official statutory guidance or seek independent legal advice to confirm their obligations under the Terrorism (Protection of Premises) Act 2025.