What Is Martyn’s Law and What Does It Mean for Property Managers

What is Martyn’s Law, and how does it affect UK property managers?

Martyn’s Law, officially titled the Terrorism (Protection of Premises) Act 2025, places a legal responsibility on certain publicly accessible premises in the UK to put in place “reasonable and proportionate” protective security measures. For UK property managers, this means showing preparedness through emergency planning, threat awareness, and documentation. It does not mean taking on policing duties or installing unnecessary infrastructure.

What Is Martyn’s Law? A Plain-English Explanation

Martyn’s Law applies to publicly accessible premises and promotes practical, site-specific protective planning. Its goal is to make safety part of daily property management without turning buildings into high-security zones.

The formal title is the Terrorism (Protection of Premises) Act 2025. It is commonly called Martyn’s Law in memory of Martyn Hett, who was killed in the 2017 Manchester Arena attack.

What does the law involve?

1. A legal requirement to plan and prepare for potential incidents.
2. Duties that depend on building type and capacity.
3. A focus on practical steps such as training and written procedures.
4. An emphasis on risk-based planning rather than physical deterrents.

Property managers are expected to understand possible threats, know how to respond, and maintain clear protection plans. Most premises can meet these requirements through training and procedures, not physical security systems.

If you’re looking for Martyn’s Law explained, this legislation builds a culture of preparedness through proportionate steps rather than enforcement powers.

Why Martyn’s Law Was Introduced and What It Aims to Prevent

Before this legislation, many public places in the UK had no legal duty to consider or plan for terrorism risks. Existing guidance from ProtectUK and the UK Government was voluntary and often applied unevenly.

Martyn’s Law was introduced to:

• Close gaps in current security requirements.

• Create a consistent national standard for public protection.

• Encourage awareness of potential threats and the need for planning.

This law supports forward planning instead of reactive security. It encourages accountability and measured decision-making without requiring excessive controls.

If you have asked why Martyn’s Law exists, the answer lies in its focus on preparing property operators to manage potential risks calmly and responsibly.

Which Properties Could Fall Under Martyn’s Law

Martyn’s Law applies to properties that are accessible to the public and meet defined capacity thresholds. This includes a wide range of building types in both the commercial and non-commercial sectors.

Examples of properties that may qualify:

• Retail parks, shopping centres, and department stores.

• Office buildings with shared or publicly accessible areas.

• Libraries, hotels, places of worship, and museums.

• Event venues, sports arenas, and stadiums.

• Mixed-use buildings and locations with public footfall.

Thresholds:

• Standard Tier: Properties with a capacity of 100 or more people.

• Enhanced Tier: Properties with a capacity of 800 or more people.

Some buildings may temporarily fall within scope due to seasonal or event-based changes. If you are unsure and wondering whether Martyn’s Law applies to your building, you should review how your property is accessed and used.

Who Is Responsible When a Property Is Professionally Managed?

Under Martyn’s Law, the duty holder is the person or organisation responsible for the way the premises is operated. This is usually the party with daily control over activities.

Depending on the arrangement, this could be:

• A freeholder who manages the entire site.

• A managing agent handling day-to-day operations.

• A leaseholder or commercial tenant with specific responsibilities.

In many buildings, responsibilities may be shared. The important steps are to:

• Clearly identify who holds the legal duty.

• Ensure everyone involved understands their role.

• Document responsibilities to avoid confusion or gaps in compliance.

How the Tier System Works and Why It Matters to Property Managers

Martyn’s Law uses a two-tier model based on the number of people a building can accommodate and how the public interacts with it.

Standard Tier

• Applies to premises with a public capacity of 100 or more.

• Requires basic training on terrorism threat awareness.

• Requires a written emergency response plan.

• Encourages low-cost, practical actions suitable for smaller or lower-risk sites.

Enhanced Tier

• Applies to premises with a public capacity of 800 or more.

• Requires a formal risk assessment specific to the building.

• Requires a written protection plan and routine reviews.

• Involves maintaining documentation that can support audits.

The two tiers reflect the level of responsibility relative to the scale and use of a site. If your property fits the Standard Tier, your duties are lighter and focused on awareness. If it meets the Enhanced Tier, the law expects more structured procedures and regular reviews.

What “Reasonable and Proportionate Measures” Mean in Real Buildings

This phrase refers to actions that reflect the building’s actual risks. Martyn’s Law does not list specific measures that every site must adopt. It gives property managers the flexibility to make informed choices.

Risk-based planning includes:

• Knowing how the space is used and who uses it.
• Understanding any potential threats.
• Taking steps that are aligned with the property’s actual risk.

Physical security only applies if justified:

• Features such as bag checks or barriers are only relevant when risk assessments show they are necessary.

Most UK property managers can meet their obligations by using training, site-specific planning, and documentation. Expensive systems are rarely required.

Examples of proportionate actions:

• Training staff to identify and report suspicious activity.
• Posting clear evacuation signage in shared or public spaces.
• Reviewing risk assessments before high-traffic events.
• Recording how and why certain safety decisions were made.

What UK Property Managers Should Be Doing Now (Before Enforcement Begins)

Even though enforcement has not started, this is the best time to begin preparing. Early planning helps avoid disruption and shows due diligence.

Recommended actions:

1. Review each building to confirm capacity and public access.
2. Identify the duty holder and put this in writing.
3. Open conversations with stakeholders such as tenants and owners.
4. Begin creating security plans and setting preparation timelines.
5. Assign internal responsibilities and track progress.

Preparing now reflects good management and allows property teams to adopt the law without rushing. It also builds trust with tenants and the public.

Where Specialist Security Advice Fits Into Martyn’s Law Compliance

You are not required to hire external advisors, but security consultants can offer useful support, especially for complex properties or sites near the Enhanced Tier threshold.

They can:

• Carry out or validate risk assessments tailored to the building.

• Recommend proportionate actions suited to your premises.

• Help create documentation that supports audits and shows compliance.

Consultants provide guidance rather than enforcement. Their input can give property managers confidence in their plans and help avoid both under- and over-preparation.

Martyn’s Law is about thoughtful planning and clear responsibility. By preparing early and focusing on proportionate actions, property managers can meet the requirements effectively and without unnecessary stress.