Heritage and museum guidance spells out what Martyn's Law means for cultural sites

The Museums Association has highlighted guidance setting out the implications of the Terrorism (Protection of Premises) Act 2025 — better known as Martyn's Law — for heritage sites. This is sector-specific signposting aimed at museums, galleries, historic houses and similar cultural venues, helping them understand how the new rules may apply to the spaces they run.

Cultural venues often have features that make readiness planning distinctive: listed buildings where physical changes are restricted, open grounds, seasonal events, and visitor numbers that swing widely between quiet weekdays and busy exhibitions or festivals. Working out how many people may reasonably be expected on site at the same time — including staff and volunteers — is the starting point for knowing which tier a site might fall into.

Standard tier covers premises where 200 to 799 people may be expected at once; enhanced tier is 800 or more. Many heritage attractions, especially during peak periods or events, could sit within scope. The duties are not yet in force — commencement is expected in spring 2027, with the exact date still to be confirmed — so this is about familiarising yourself, not acting under pressure.

Use sector guidance like this to think through your own site: estimate realistic peak attendance, consider how grounds and event days change the picture, and start conversations with trustees, volunteers and event partners. The SIA's notification process is not yet live, so there is nothing to register at this stage — the value now is in quiet preparation.