Martyn's Law tier checker

Answer two questions to see whether your premises would fall into the standard or enhanced tier under Martyn's Law — and what that would mean.

Indicative only, based on the headline capacity thresholds. The Act is not yet in force (expected spring 2027). Confirm against the Act and SIA guidance.

1. What best describes the premises?

Martyn's Law applies to qualifying premises and events with a qualifying use under the Act (Schedule 1) that are not excluded. Some uses have special tier treatment.

2. How many people (staff and public) may be present at the same time?

About Martyn's Law tiers

Under the Terrorism (Protection of Premises) Act 2025, qualifying premises and events fall into a standard tier (200–799 people present at the same time) or an enhanced tier (800 or more). Standard-tier premises focus on public protection procedures; enhanced-tier premises and events add public protection measures and must document them for the regulator, the Security Industry Authority (SIA). Some uses have special treatment: childcare, primary, secondary and further education settings and places of worship stay in the standard tier even at 800 or more, while higher education does not. Whether the Act applies also depends on the premises having a qualifying use under Schedule 1 and not being excluded.

For the full picture, read Martyn's Law explained. To keep procedures, training and evidence in order in the meantime, see how Complys handles training and documented procedures.

Martyn's Law tier checker — FAQs

Is this a legal determination of my Martyn's Law duties?

No. It is an indicative guide based on the headline capacity thresholds. The full scope, definitions and exclusions are set out in the Terrorism (Protection of Premises) Act 2025 and its guidance — confirm your position against those and the SIA's guidance.

Is Martyn's Law in force yet?

Not yet. The Act has passed but the duties are expected to come into force in spring 2027, with an implementation period to prepare. This checker helps you plan ahead.

What counts as the number of people present?

The tiers are based on how many people may be present at the premises (or event) at the same time — this includes staff and the public. This checker uses the headline bands; the Act sets out exactly how capacity is judged.