Martyn’s Law Fines and Penalties: How the SIA Will Enforce

The Terrorism (Protection of Premises) Act 2025, known as Martyn's Law, received Royal Assent on 3 April 2025. It requires many publicly accessible venues and events across the UK to prepare for the risk of a terrorist attack. A law like this only works if there are consequences for ignoring it.

To implement it properly in your premises, you must know who will enforce Martyn's Law, what powers they hold, and what fines you could face. The information depends on whether a site falls into the standard or enhanced tier, so the same breach can carry very different consequences. Knowing what Martyn's Law is and which premises it covers is the first step in judging your own exposure.

Why the SIA Sits at the Centre of Martyn's Law Enforcement

The Act establishes the Security Industry Authority (SIA) as the regulator. According to the Home Office regulator, sanctions and enforcement factsheet, the SIA will seek to support, advise and guide those responsible for premises and events. Formal enforcement action targets serious or persistent non-compliance.

How Inspections and Information Notices Come First

Before issuing any sanction, the SIA needs evidence of how a venue or event is performing. An inspector will usually give at least 72 hours' written notice before a visit. Where access is needed sooner, is refused, or notice would defeat the purpose of the visit, the inspector can apply for a warrant.

During an inspection, the inspector can view documents, observe activities, inspect equipment, take photographs or records and ask for an explanation of any relevant document. An inspector can also issue an information notice requiring security information or attendance at an interview.

The Three Civil Sanctions the SIA Can Use

1. Compliance notices - The SIA can issue one when it has reasonable grounds to believe a responsible person has failed, or is failing, to meet a requirement under the Act. The notice requires the person to meet that requirement within a set period.
2. Restriction notices - These apply only to enhanced tier premises and qualifying events. The SIA can use one where it believes appropriate public protection procedures or measures are missing, and where restrictions are necessary to reduce the risk of physical harm to the public.
3. Penalty notices - These impose a financial penalty for non-compliance. The amounts are covered next.

What Martyn's Law Fines Look Like for Standard and Enhanced Tier Premises

The SIA can issue non-compliance penalties of up to £10,000 for standard duty premises. For enhanced duty premises or qualifying events, the maximum is £18 million or 5% of worldwide revenue. Section 18 of the Act sets the £10,000 ceiling for standard duty premises and provides the higher figure for the enhanced tier.

Other penalties sit alongside these.

• The maximum penalty for failing to attend an interview is £5,000.
• Where a penalty is issued for failing to comply with a compliance or restriction notice, daily penalties can follow if non-compliance continues after the date the penalty is payable.
• Daily penalties can reach £500 per day for standard duty premises.
• For enhanced duty premises or qualifying events, they can reach £50,000 per day.

These are maximums, and the SIA does not have to impose them.

How the Act Shapes the Size of a Penalty

When determining the amount, the SIA must consider the effects of the non-compliance, any action taken to remedy it, and the person's ability to pay. A venue that spots a gap and fixes it promptly is in a stronger position than one that ignores a notice.

What the SIA Has and Has Not Published on Enforcement Guidance

The SIA must produce guidance on how it will exercise its functions, including its enforcement powers, and the Home Secretary must approve it before publication. A draft went out for public consultation until 12 June 2026. The SIA said it planned to publish its final guidance and a consultation report in autumn 2026.

As of posting, the consultation page on GOV.UK still says the SIA is analysing feedback, and no outcome is posted there. We could not confirm that the SIA has published the final guidance. This article therefore does not describe how the SIA will make compliance decisions or calculate individual penalties beyond what the Act and the Home Office factsheet state. The SIA's Martyn's Law collection on GOV.UK is the place to check for the latest position.

When Non-Compliance Becomes a Criminal Matter

The Act creates criminal offences. It is an offence to fail to comply with an information notice. For enhanced duty premises and qualifying events, it is also an offence to fail to comply with a compliance or restriction notice.

The Home Office expects penalty notices to be the primary enforcement method. In the most serious cases, where it is proportionate and in the public interest, the SIA may refer those responsible for prosecution.

Your Right to Respond and Appeal

The SIA must notify the affected party before issuing these notices and give them an opportunity to make representations. The one exception is where there is an urgent need to issue a restriction notice. After a notice is issued, there is a right of appeal to the Tribunal. A clear record of your decisions and security arrangements is the foundation of any response or appeal.

When Enforcement Starts and What to Do Before Then

The duties are not yet in force. The Home Office has confirmed an implementation period of at least 24 months from Royal Assent and will confirm the exact commencement date through Parliament. The SIA has said it expects the law to come into force from spring 2027.

Sensible steps for the window ahead include the following.

• Work out whether your premises or event qualifies, and which tier applies.
• Identify the responsible person and, for enhanced tier sites, the senior individual.
• Read the Home Office statutory guidance, and the SIA's section 12 guidance once finalised.
• Document your risk assessments, procedures and staff training.
• Record how deliveries and incoming post are received and handled on site.
• Respond promptly and in writing to any SIA information request or notice.

The delivery bullet deserves a closer look. Neither the Act nor the Home Office factsheet sets mailroom-specific rules, so this is good practice rather than a legal requirement. Even so, every parcel and letter is a routine point where items from outside enter a building. Strong mailroom management means each item is logged on arrival, with a named handler and a clear handover. Effective parcel management extends that record from the moment a parcel is received to the moment it reaches its recipient. If an inspector ever asks how your site handles day-to-day activity, a timestamped trail is far easier to present than staff recollection.

Compliance Costs Less Than Enforcement

The SIA intends to lead with advice and support, which is good news for organisations that engage early and act in good faith. The consequences of ignoring the law are still serious, from compliance notices and operating restrictions to fines of up to £18 million for the largest sites. The strongest position is to arrive at commencement with procedures in place and a record that proves it.

Build Your Evidence Trail Before the SIA Asks for It

Most organisations will not struggle because they ignored Martyn's Law. They will struggle because they cannot show what they actually do every day. Deliveries, visitors and incoming post all leave gaps when nothing is recorded, and gaps are what notices and penalties are built on.

If you want to see where your current processes would stand, talk to us. We can walk through how your mailroom and parcel workflows are handled today and where a clearer, documented approach would help you show your work. The conversation is quick, and it is far easier to have it now than after a notice lands.

Martyn's Law Enforcement Expert FAQ

What is the maximum Martyn's Law fine for standard tier premises?
The SIA can issue penalties of up to £10,000 for standard duty premises, plus daily penalties of up to £500.

What is the maximum Martyn's Law fine for enhanced tier premises?
Enhanced tier penalties can reach £18 million or 5% of worldwide revenue, whichever is greater, plus £50,000 daily penalties.

How does the SIA enforce Martyn's Law?
The SIA inspects premises, gathers information, then issues compliance, restriction or penalty notices for serious or persistent non-compliance.

Why do daily penalties matter under Martyn's Law?
Daily penalties apply when non-compliance with a notice continues after the penalty is payable, increasing financial exposure.

What rights of appeal exist against SIA notices?
Responsible persons can appeal to the Tribunal after a notice is issued, and the SIA must usually allow representations first.

Why should organisations prepare before Martyn's Law commences?
The law is expected to commence from spring 2027, so early preparation reduces the risk of notices and penalties.

Disclaimer: This article is general information and does not constitute legal advice. Check the latest guidance from the Home Office and the SIA before making compliance decisions.