Martyn's Law Capacity Assessment for Standard and Enhanced Tier

Martyn's Law (the Terrorism (Protection of Premises) Act 2025) sorts qualifying premises and events into two tiers using a single test: how many individuals may reasonably be expected to be present at the same time. The count includes your staff, not just your customers, visitors or audience.

Standard duty premises are those where 200 to 799 individuals may be present at once. Enhanced duty premises and qualifying events are those where 800 or more may be present. Getting this number right determines which set of duties applies to you.

The Act received Royal Assent on 3 April 2025 and is regulated by the Security Industry Authority (SIA). There is an implementation period of at least 24 months, so the Act is expected to come into force in Spring 2027, and there is no legal duty to comply until commencement.

This guide explains how to carry out a capacity assessment, where to get your numbers, and how occasional higher-attendance events can pull a venue into scope. It is written for owners and managers who need a defensible answer to one question: standard or enhanced.

The capacity thresholds and tier definitions are set out in the Terrorism (Protection of Premises) Act 2025, with practical detail in the section 27 statutory guidance published on 15 April 2026.

The two thresholds explained

The whole assessment turns on two numbers. Premises fall into the standard tier where 200 to 799 individuals may reasonably be expected to be present at the same time, and into the enhanced tier where that figure reaches 800 or more.

Below 200 individuals, a premises is not in scope and the duties do not apply. The 200 figure is the entry point to the regime, and the 800 figure is the line between the two tiers.

Education settings are treated differently. Schools, colleges and similar settings remain in the standard tier regardless of capacity, where they are above the 200 threshold, so a large school does not become an enhanced duty premises by virtue of its numbers. The detail is in the government's guidance for education settings.

How to count: everyone, including staff

The figure you need is the total number of individuals who may reasonably be expected to be present at the same time. This means your headcount includes staff, contractors and any other workers on site, alongside customers, visitors, members or audience.

A common mistake is to count only paying customers or ticketed attendees. A venue with a customer capacity of 750 and 60 staff on a busy shift has 810 individuals present, which places it in the enhanced tier.

Assess the number against peak use, not an average day. If your numbers reach the threshold at the busiest expected point, that is the figure that decides your tier.

Where to get your numbers

You do not need to start from scratch. Most premises already hold data that supports a capacity assessment.

• Fire safety occupancy limits, which give a maximum safe number of people for the premises.
• Licensing capacity figures, where the premises holds a premises licence with a stated capacity.
• Ticketing and booking records that show actual peak attendance.
• Site data such as floor area, layout and the calculations used for your fire risk assessment.
• Staffing rotas showing the largest number of workers present at one time.

Fire safety occupancy limits are a sensible starting point because they already represent a maximum for the space. Where your real peak attendance sits well below a high fire safety limit, use the figure that genuinely reflects how many people may reasonably be expected to be present at once.

Occasional events can bring you into scope

A premises that normally sits below a threshold can be pulled into scope, or up a tier, by occasional higher-attendance events. The test is about the numbers that may reasonably be expected to be present, so a recurring spike counts.

A community venue that hosts 150 people most weeks but runs an annual event drawing 850 should treat that event as relevant to its assessment. The same applies to a venue that hires out a larger hall a few times a year.

Review your assessment whenever your pattern of use changes, such as adding a large seasonal programme, extending opening, or taking on regular bookings that lift your peak numbers.

Quick-reference: standard versus enhanced

Feature	Standard duty (200 to 799)	Enhanced duty (800 or more)
Capacity (including staff)	200 to 799 individuals	800 or more individuals
Core obligation	Public protection procedures (section 5)	Procedures plus public protection measures (section 6)
Focus areas	Evacuation, invacuation, lockdown, communication	Monitoring, movement of individuals, physical safety and security, security of information
Senior responsible individual	Not required	Must be designated
Compliance document for the SIA	Not required	Required
Maximum penalty	£10,000 (daily penalty up to £500)	£18 million or 5% of qualifying worldwide revenue, whichever is greater (daily penalty up to £50,000)

What standard duty premises must do

If your assessment puts you in the standard tier, section 5 requires appropriate, reasonably practicable public protection procedures across four areas. These are expected to be simple and low cost, with no requirement to buy equipment.

• Plan evacuation procedures to get people out of the premises safely.
• Plan invacuation procedures to move people to safety inside the premises.
• Plan lockdown procedures to secure the premises against a threat.
• Plan communication procedures to alert staff and the public.

What enhanced duty premises must do

If your assessment puts you in the enhanced tier, section 6 adds public protection measures on top of the standard procedures. You must also put governance and documentation in place.

• Implement measures across four categories: monitoring the premises, movement of individuals, physical safety and security, and security of information.
• Designate a senior individual responsible for compliance.
• Prepare a compliance document recording the procedures and measures and an assessment of how they reduce vulnerability and the risk of harm.
• Provide that compliance document to the SIA.

Common errors to avoid

• Counting only customers or ticket holders and leaving staff and contractors out of the total.
• Using an average day rather than peak expected attendance.
• Ignoring occasional high-attendance events that lift numbers above a threshold.
• Assuming a large education setting is enhanced tier, when education settings remain standard tier above the 200 threshold.
• Treating the assessment as a one-off, rather than reviewing it when your pattern of use changes.
• Relying on a fire safety limit that is far higher than the number who may realistically be present at once, or ignoring fire safety data altogether.

Enforcement and penalties

The SIA can use compliance notices, restriction notices and monetary penalties to enforce the regime. For standard duty premises the maximum penalty is £10,000, with a daily penalty of up to £500.

For enhanced duty premises and qualifying events the maximum is £18 million or 5% of qualifying worldwide revenue, whichever is greater, with a daily penalty of up to £50,000. The SIA's draft section 12 enforcement guidance is out for consultation, closing at 11:59pm on Friday 12 June 2026, with further detail in the SIA consultation announcement.

How Policy Pros can help

Getting your tier right is the foundation for everything else under Martyn's Law, because it decides whether you need procedures alone or procedures plus measures and a compliance document. We help you assess capacity against peak use and your existing fire safety and site data, then build the documentation that matches your tier.

Start with our Martyn's Law compliance documentation service for end-to-end support, or read the full Martyn's Law 2027 compliance guide for the wider picture.

Once you know your tier, move on to the detail: standard tier procedures for premises in the 200 to 799 band, or the enhanced tier compliance document for premises at 800 or more. You can also work through our capacity assessment guide for a step-by-step walkthrough.