How the verdict is worked out.
Every verdict traces back to the Terrorism (Protection of Premises) Act 2025 and the Home Office statutory guidance. Here is exactly what the tool checks, the decision rules it applies, and where its limits are, so you can judge the output for yourself. Content current as at 12 July 2026.
The inputs that decide it
The scope and tier of a premises or event turn on a small number of facts. The tool collects exactly those:
- Premises or event. The two categories are assessed differently.
- Use. Whether the use is one of the Schedule 1 categories that can bring a premises into scope.
- Capacity band. The greatest number of people reasonably expected at the same time, from time to time, including staff and volunteers.
- Event access. For events, whether access is controlled by ticket, payment, membership, invitation or express permission.
- Control and responsible-person type. Who controls the premises for the use, and whether that person is an individual or an organisation, which decides the responsible person and the senior-individual duty at enhanced tier.
The decision rules
The tool applies the thresholds set out in the Act and the guidance, in this order:
Events
An event qualifies only where 800 or more people may reasonably be expected at the same time and access is controlled. Below 800, or without controlled access, it is not a qualifying event, though if it takes place at premises that are themselves in scope, the premises duties can still apply. A qualifying event sits in the enhanced tier.
Premises
- If the use is not a Schedule 1 use, scope is uncertain and you should check the category list.
- If the premises is an excluded type under Schedule 2 (for example a Parliament or devolved government building, an open-access park with no entry controls, or transport premises already covered by separate security legislation), it is likely out of scope. Confirm the exact exclusion.
- Under 200 people: out of scope on capacity.
- 200 to 799 people: in scope, standard tier.
- 800 or more people: in scope, enhanced tier.
How the report is built from the rules
The report runs your answers through the same rules, then fills in the sections that depend on them: your responsible person from your control answer, your itemised duties from your tier, a checklist tailored to standard or enhanced, and the key dates. The free check and the report use one set of rules, so the two never contradict each other.
What the tool does not do
It gives a scoping verdict, not a full assessment.
It tells you whether you are in scope and which tier, and what the duties are. It does not write your evacuation plan, choose your enhanced-tier measures, or draft the mandatory document. Those are the next steps the report points you to.
It relies on the answers you give.
If your capacity band is wrong, the tier will be wrong. That is why the tool repeatedly nudges you to re-count including staff and to use the greatest expected simultaneous number.
Borderline uses and exclusions need the exact wording.
Schedule 1 uses and Schedule 2 exclusions have precise statutory definitions. For an edge case, the report flags it as borderline and points you to the Act, rather than forcing a false yes or no.
It is not legal advice.
It is an information tool reflecting the Act and the published guidance on the date shown. It does not create a professional relationship and is not a substitute for advice on your specific facts.