Capacity is not the test. Under the Terrorism (Protection of Premises) Act 2025, scope and tier are decided by the number of individuals reasonably expected on site from time to time — not by the number the building is calculated to hold.

So a store whose fire capacity calculation says around a thousand, and which has never had more than 600 people on site in over a year, is standard tier rather than enhanced. That position is available, and it has to be evidenced. A regulator who sees the capacity figure will want stringent evidence for the smaller number.

A fire capacity calculation tells you how many people can safely be in a space, given exit widths and travel distances. It is a ceiling.

Expected attendance is a forecast: how many people you reasonably expect on the premises from time to time, counting staff and contractors as well as customers. That is the figure the Act is built on, for scope and tier alike. Retail is where the two diverge most, because a store’s ceiling is set by its floor area and its attendance by its trading pattern. Capacity is worth using as one input when estimating a peak you never counted, never as the answer.

Standard tier is 200 to 799 individuals reasonably expected on site. Enhanced tier is 800 or more. Both figures describe expected attendance, so a capacity calculation above 800 does not put a premises in the enhanced tier.

The tiers are not the same amount of work. Standard tier is the four public protection procedures — evacuation, invacuation, lockdown and communication, as four distinct items. Enhanced tier adds public protection measures.

Here is the case as it arrives. The fire capacity calculations say the site holds around a thousand. The records say that in over a year it has never had more than 600 people on site at any one time. Capacity points at the enhanced tier. The real number says standard.

Provided you can show evidence of that to the regulator, and you are able to justify it, you should be able to say that you are not in the enhanced tier — you are in the standard tier. Be precise about the claim, though. Not that capacity is irrelevant, and not that the smaller number is accepted automatically. Only that expected attendance is the test, and yours is 600.

Do be cautious. If the regulator comes along and sees your fire capacity calculations, you are going to have to have some pretty stringent evidence to show that the higher figure never materialises. That is a reason to prepare the position rather than avoid it: the capacity figure is already in your building, pointing the other way.

A comfortable margin helps. A figure just under 800, or just under 200, is a different conversation — where two honest estimates exist, the higher one is the safer figure to work from, because a borderline premises should expect the regulator to run its own calculation.

The aim is a sustained record, not a recollection:

• Footfall data over a long enough period. A year or more, including the peaks — Christmas trading, sale weekends, launches and late-night events. One quiet quarter proves little.
• Door counters and till records, used together. Counters give you people, transactions a floor under the estimate, and the gap between them is worth understanding first.
• Staffing rosters for the busiest days. Everyone on site counts, so the peak figure includes the team that was working it.
• A reason the peak is capped where it is. Trading format, opening hours, no standing or ticketed events. Explaining why the ceiling is never approached turns data into a justification — and a format change or a new event programme puts the number back on the table.

Landing in the standard tier settles which duties apply. It does not remove them. The four procedures have to be in place so far as is reasonably practicable, and that test is not a size test — it weighs likely effectiveness against burden, taking account of the nature and use of the premises, its location, its visitor profile, the resources available and the mitigation already there.

Nothing is submitted for approval at standard tier, and you have to be able to evidence those procedures if inspected. Tier evidence and procedure evidence end up in the same conversation anyway.

Our Am I in Scope? tool asks for the attendance you expect and returns your scope position from it, so establishing that figure is the job to do first.

Prova Risk works out what is reasonably practicable for your site, builds all four procedures around it, holds the training and exercise records, and produces a single compliance document you can put in front of a regulator. £399 per year per site.

• Counting peak attendance rather than an average week
• Counting attendance without a clicker on the door
• What “so far as is reasonably practicable” actually means
• Standard tier and enhanced tier: the difference
• How do I know if my premises reaches the 200-person threshold?
• Does Martyn’s Law only apply to large premises?
• Martyn’s Law hub