How a venue's main use shapes where it sits under Martyn's Law
Published
A legal update looks at the "principal use" idea — how the main purpose of a premises helps decide whether it falls in scope of Martyn's Law and at which tier. Here is what that means for operators as they prepare.
What happened
A legal commentary from The National Law Review has set out thinking on the "principal use" rules under the Terrorism (Protection of Premises) Act 2025. The point is that a building is assessed on what it is mainly used for. That main use helps decide whether the premises are in scope and, if so, whether they sit in the standard tier (200 to 799 people) or the enhanced tier (800 or more). The headcount includes staff.
What it means for venues
Many sites have more than one activity under one roof. A community hall might host markets, services, parties and the odd large event. The principal use idea is a reminder that scope is about the premises as a whole and how it is normally used, not a single busy night. If you run a mixed-use building, it is worth being clear about its main purpose and the realistic number of people present at the same time.
A calm note on timing
None of these duties are enforceable yet. Commencement is expected in spring 2027, and the exact date is still to be confirmed. The Security Industry Authority will be the regulator, and its notification process is not yet live. There is time to understand the rules without rushing.
What to do now
Think through how your premises are mainly used and roughly how many people could be present together on a typical busy occasion, counting staff. That rough figure gives you a sense of whether you are likely to be in scope and at which tier. Keep this under review as your activities change, and treat it as preparation rather than a final legal judgement.
This is our plain-English summary. Read the original in full at The National Law Review.