The tier will usually depend on the greatest number of people, including staff, that can reasonably be expected to be present at the same time, from time to time — together with the other qualifying criteria in the Act.
The general guide
- Fewer than 200 people — the premises will generally fall outside Martyn's Law, although the other criteria and any applicable exceptions should still be considered.
- 200–799 people — Standard Tier. If the other qualifying criteria are met, the premises will normally fall within the Standard Tier.
- 800 or more people — Enhanced Tier. If the other qualifying criteria are met, the premises will normally fall within the Enhanced Tier and additional requirements apply.
Qualifying events are treated differently from premises, and are subject to Enhanced Tier requirements where the relevant criteria are met.
"Reasonably expected", "at the same time", "from time to time"
Each of those phrases is doing something, and each is a place organisations get the answer wrong.
Reasonably expected — not theoretical maximum, not typical Tuesday
This is not the number the building could physically hold if you removed the furniture, and it is not the average across the year. It is the number you would honestly expect at the busy times, in the normal course of what you do.
At the same time — the peak, not the total through the door
A café that serves 900 people across a day but seats 60 is not an 800-plus premises. A venue that turns over two audiences of 500 in an evening has a peak of 500 plus whatever overlap occurs during changeover — which is worth thinking about, because changeover is often the busiest and least controlled moment of the night.
Including staff
This is the most common error. Occupancy figures taken from fire documentation often relate to something else, or exclude staff. A 780-capacity venue with 40 staff on a busy night is not a Standard Tier premises on those numbers.
From time to time — the busy exception counts
If the premises reaches the higher figure occasionally — a seasonal peak, a fixture, a once-a-month event — that still counts. "Usually we are well under" is not the test.
Work the number out properly, and write down how you got it
Whatever figure you land on, record the reasoning: which areas, what layout, what event type, staff included, and what you excluded and why. A number with reasoning behind it is defensible. A number on its own is a guess someone else will have to re-do.
The exceptions
There are important exceptions that override the capacity guide:
- Qualifying places of worship remain within the Standard Tier even where 800 or more people may be present.
- Premises used for childcare, primary or secondary education, or further education likewise remain within the Standard Tier even at 800 or more.
These are not loopholes to be grateful for — they reflect a judgement that the Standard Tier procedures are the proportionate response for those settings. The obligation to have workable evacuation, invacuation, lockdown and communication arrangements does not go away.
Capacity alone does not determine it
The type and use of the premises, the number of people reasonably expected to be present, exclusions and special provisions all need to be considered. A premises can sit above a threshold and still be out of scope; it can sit below one and still be caught by another criterion.
If your premises does more than one thing — a school hall hired out at weekends, an office with a public café, a church with a community centre attached — work through each use separately before concluding.
If you are near a threshold
Two practical suggestions.
First, do not design your operation around staying under a number. If you are at 780 on a good night, you are close enough that the Enhanced Tier questions are worth thinking about anyway, and a single successful season could move you.
Second, prepare regardless. Organisations below 200 frequently choose to do this work anyway, because a written evacuation plan, a safer area, a way of telling staff what is happening and a list of who is responsible for what are simply good practice — and because insurers, licensing authorities, funders and clients increasingly ask.
Where the definitive answer is
For definitive information about whether your premises or event is within scope, refer to the current statutory guidance issued under the Terrorism (Protection of Premises) Act 2025.
This article is general guidance, not legal advice, and it is not a substitute for the statutory guidance. For definitive information about whether your premises or event is within scope and what is required, refer to the current statutory guidance issued under the Terrorism (Protection of Premises) Act 2025.