What is the difference between the standard and enhanced tiers under Martyn's Law?

Updated 2026-10-04 · UK law and HSE guidance

Short answer

Once the substantive provisions commence, standard tier premises, which generally expect 200 to 799 people at the same time, must notify the SIA and put appropriate, reasonably practicable public protection procedures in place. Enhanced tier premises generally expect 800 or more people and must do those things plus implement public protection measures, document compliance, keep measures under review and designate a senior individual where the responsible person is an organisation. Qualifying events are also subject to the enhanced requirements.

Key facts
Standard threshold	200 to 799 people at the same time
Enhanced threshold	800 or more people at the same time
Both tiers	Notification and four public protection procedures
Enhanced additions	Measures, documentation, review and senior oversight
Threshold method	Greatest number reasonably expected, including staff

How the tier is decided

The tier is based on the greatest number of individuals reasonably expected to be present at the same time from time to time for the relevant use. Staff, volunteers, contractors and members of the public can all count. It is not enough to use only ticket sales, seated capacity or fire capacity if that would not reflect the people reasonably expected to be there together.

Premises must also meet the other scope conditions: they must contain a building, be wholly or mainly used for a Schedule 1 purpose and not be excluded. A site that can hold 800 people is not automatically enhanced tier if it is not reasonable to expect that number to be present from time to time.

Standard tier: at least 200 but fewer than 800
Enhanced tier: 800 or more
Use evidence such as safe occupancy limits, ticketing records, staffing, rotas, booking data and past attendance where relevant
Reassess the figure if the use, layout or attendance pattern changes

Duties shared by both tiers

Every responsible person in either tier must notify the SIA when the notification duty commences. They must also ensure, so far as reasonably practicable, that appropriate procedures are ready for evacuation, invacuation, lockdown and communication if an attack is suspected or occurring at the premises or in its immediate vicinity.

Appropriate means suitable for the premises. Reasonably practicable means balancing the safety benefit against the cost, time and difficulty of taking the step. People working at the premises need to know the procedures well enough to put them into practice.

Evacuation: move people out or away from danger
Invacuation: move people to a safer place inside
Lockdown: secure the premises to control entry or exit
Communication: alert people and give instructions where safe

Standard tier requirements

The standard tier is focused on practical preparedness. The Act does not require a standard tier responsible person to prepare or send the SIA a document describing its procedures. Home Office guidance nevertheless recommends documenting them because this helps staff understand them and can help demonstrate compliance during an inspection.

There is no prescribed Martyn's Law training course, mandatory Standard Terrorism Evaluation form or automatic requirement to install equipment or alter the building. A physical change could still be reasonably practicable in a particular case, but the decision must reflect the actual premises and resources.

Notify the SIA when the legal notification system begins
Put the four appropriate procedures in place
Make workers aware of the procedures
Co-ordinate with other responsible persons where the Act requires it

Enhanced tier requirements

Enhanced tier premises and qualifying events must meet the shared duties and take further steps. They must ensure appropriate and reasonably practicable public protection measures are in place to reduce both physical harm and vulnerability to attack. The four statutory categories of measure concern monitoring, movement, physical safety and security, and security of information.

The responsible person must keep the measures under review. It must document the procedures and measures, assess how they meet the statutory objectives, keep that document current and provide it to the SIA. After a revision, the updated document must be provided within 30 days. If the responsible person is an organisation, it must designate a qualifying senior individual to oversee compliance.

Monitoring premises, events and their immediate vicinity
Controlling movement into, out of and within the site
Protecting physical safety and security
Protecting information that could assist an attack
Recording measures that are planned but cannot reasonably be implemented immediately

Events and special cases

A public event with 800 or more people expected at the same time is a qualifying event only if it also has an entry condition that is checked, is not at existing enhanced tier premises and is not within an exclusion. A one-off qualifying event is governed by the enhanced requirements even where the underlying location is normally outside scope or standard tier.

Places of worship and premises used for childcare, primary education, secondary education or further education are treated as standard tier when 200 or more people are reasonably expected, even at 800 or above. Events there are not qualifying events. Universities and other higher education premises follow the ordinary thresholds.

Check premises and event scope separately
Identify who controls the location for the event
Document how premises and event duty holders will co-ordinate
Do not assume a large school or place of worship is enhanced tier

Sources

This guide summarises UK law and HSE guidance for small businesses. It is not legal advice; check the sources and your own circumstances.