Museums and heritage sites: what Martyn's Law means for your venue

A museums and heritage trade title has published an overview of Martyn's Law for cultural venues. The law, formally the Terrorism (Protection of Premises) Act 2025, received Royal Assent in April 2025. The article sets out what museums, galleries and heritage attractions should understand as the sector starts to prepare. Worth noting: the duties are not yet in force. Commencement is expected in spring 2027, with the exact date still to be confirmed.

Museums, galleries and heritage sites often welcome large numbers of visitors, and many sit close to or above the thresholds in the Act. Premises where 200 to 799 people may reasonably be expected at the same time fall into the standard tier. Premises expecting 800 or more fall into the enhanced tier. The headcount includes staff and volunteers, not just paying visitors. Sites with multiple buildings, outdoor grounds or busy event days will want to think carefully about how many people gather at once.

Visitor numbers can swing a lot through the year, with seasonal peaks, school trips and special events. Listed buildings and historic settings bring their own constraints on what physical changes are practical. None of this requires action today, but it helps to start mapping where your busiest moments occur and how people move through your spaces.

Use the time before commencement to familiarise yourself. Estimate your realistic peak attendance, including staff and volunteers, to get a sense of which tier you may fall into. Note that the Security Industry Authority will be the regulator, and its notification process is not yet live. There is no need to register or notify anyone yet. Treat this as a chance to plan calmly rather than react under pressure.