Statutory guidance

Non-statutory supplementary document A: Methods for assessing the reasonable expectation of individuals present at the premises and events (accessible)

Updated 27 April 2026

This non-statutory supplementary document is intended to provide supporting information in relation to the Terrorism (Protection of Premises) Act 2025 Statutory Guidance. ^{[footnote 1]} The Terrorism (Protection of Premises) Act 2025 is subsequently referred to as ‘the Act’.

1. To ensure compliance with the requirements of the Act, it is first necessary to understand whether the premises or event fall within the scope of the Act. That requires calculating the number of individuals that can be reasonably expected to be present at the same time, either at an event or from time to time at the premises.

2. Set out below are some non‑exhaustive examples of methods for calculating the number of individuals, but these methods are not prescriptive or exhaustive and allow for flexibility and judgement to ensure that an accurate assessment of numbers expected can be reached. The assessment should be kept under review to ensure it remains reasonable if circumstances change, such as if a large restaurant becomes busier at peak times after receiving positive reviews.

3. The number of individuals should include all individuals on the premises or at the event. This figure must include staff working at the premises in connection with a Schedule 1 use. ^{[footnote 2]} Only those attending or working in the part of the premises used for a Schedule 1 use should be included in the assessment. When assessing the reasonable expectation of individuals, the following factors are likely to be relevant:

• What is the nature / type of the premises or event?
• How are the premises used, or what is the purpose of the event?
• Are there areas of the premises or event that are excluded from the assessment?
• How many staff will be present, as well as the public?
• What is the most appropriate method to establish a figure which accurately reflects the numbers of individuals who will be present?

4. The Security Industry Authority (SIA) can require the responsible person to provide information about how the assessment was carried out using information-gathering powers at Schedule 3 to the Act. ^{[footnote 3]} The table at figure Figure 1 outlines the methods that a responsible person could use to establish an assessment figure. In all cases, the expected number of staff must also be considered. The assessment is important because it enables individuals and businesses to understand whether their premises or event fall in scope of the Act.

Premises: reasonable to expect at the same time, from time to time

5. The assessment is of the number of individuals who may be expected to be at the premises at the same time, from time to time.

6. The term ‘at the same time’ is a common term and is understood to mean together or simultaneously. Within the Act, the term refers to individuals being present on the premises together at any one time.

7. The term ‘from time to time’ is a common term and is understood to mean occasionally. Within the Act, the term refers to how often 200 or more individuals can reasonably be expected to be present on the premises and recognises the fact that many types of premises will experience fluctuations in the number of individuals that they have on the premises.

8. The thresholds may be met, for example, only on certain nights of the week or at certain times of the year, but can overall be met from time to time. It may be relevant to consider external events, for example, a major televised sports event meaning higher than usual attendance at a pub or entertainment complex. Where that is the case, and similar attendance can reasonably be expected in the future, the premises will fall in scope. ‘From time to time’ does not refer to an average attendance, for example, over a day or a week. ‘From time to time’ also does not bring within the scope of the Act premises that unexpectedly meet the threshold as a one-off, and could not reasonably be anticipated to do so again.

Events: reasonable to expect at some point

9. To meet the attendance criterion for a qualifying event, it should be reasonable to expect that 800 or more individuals will be present at the event at the same time, which includes staff. This criterion will be met if the threshold is met at any time (‘at some point’) during the event. For example, if an event takes place over a four-day period, and the event organiser only expects to meet this criterion during the event’s final day, the event will still be in scope of the Act’s requirements for the duration of the event.

10. The organiser can use any reasonable method of assessing the number of individuals who may be expected to be present at the event. For example, the organisers of many events will know when people typically arrive, how long they typically stay, the precise numbers of tickets that have been sold and when the 800 figure is likely to be reached. Other methods include looking at the numbers of individuals who have attended the event in the past, or utilising fire safety requirements to understand the number of individuals who may safely be accommodated at the premises.

Immediate vicinity

11. The term ‘immediate vicinity’ means an area close to the premises, but there is no fixed distance associated with this term. The responsible person does not need to take account of the immediate vicinity when making the assessment of the reasonable expectation of individuals that will be present. This is because, for the purposes of the Act, the relevant figure is the number of individuals that can reasonably be expected on the premises or at the event.

Methods that could be used to assess the reasonable expectation of the number of individuals present

12. This section details some possible methods that the responsible person could use to assess the reasonable expectation of the number of individuals present at premises or events. The non‑exhaustive examples of methods within this document are not prescriptive, but allow for flexibility and judgement to ensure that an accurate assessment is reached. The assessment should be kept under review to ensure it remains reasonable if circumstances change.

Figure 1: Methods to assess reasonable expectation of the number of individuals at the same time for premises and events

Methods to assess reasonable expectation (assessment must include all individuals on the premises or event including staff.)

Method	Description
A: Safe occupancy for fire safety purposes	Maximum number of individuals that can be reasonably accommodated in a building for fire safety purposes.
B: Historic attendance data	Information such as records taken from previous years which reflect actual usage at peak times.
C: Fixed seating and / or fixed standing positions	The number of fixed seats and / or fixed standing positions (depending on the nature of the business).
D: Tickets and pre-registration	The maximum number of tickets that can be issued or the number of individuals that can register prior to entry can be used to establish an upper limit on attendance.
E: Restrictions	For premises and events that impose restrictions on attendance, for example, a maximum attendance / capacity figure attached to an alcohol and entertainment licence, this figure can be used to determine the number of individuals expected to be present.
F: Other means of assessing	Other means can be used to assess numbers, together with a justification and supporting evidence.

A: Safe occupancy for fire safety purposes

13. Those responsible for qualifying premises or events could assess the number of individuals who can reasonably be expected to be present at the same time, based on the number of individuals who can safely occupy the premises or event. The number of individuals should include all individuals on the premises or at an event, including staff.

14. Many premises may already have a safe occupancy number for fire safety purposes. The safe occupancy number is calculated in accordance with the methods set out in relevant guidance, which applies to buildings only. For example, the guidance that accompanies the Building Regulations 2010 for England and Wales sets out two methods to calculate how many individuals can safely be accommodated inside a building (or equivalent structures). ^{[footnote 4]}

Example 1: A café establishes a fire safety safe occupancy figure of 250 individuals, and it is often full to this capacity. This figure includes those working at the café. The responsible person assesses that it is reasonable to expect 250 individuals at the premises at the same time. The café therefore falls within the standard tier.

Example 2: A café establishes a fire safety safe occupancy figure of 180 individuals. This figure includes those working at the café. The café also has outdoor seating for 30 individuals, and it is often full to this capacity. The responsible person assesses that it is reasonable to expect 210 individuals at the premises at the same time. The café therefore falls within the standard tier.

B: Historic attendance data

15. Historic data showing actual numbers of individuals present on the premises or at the event can be used to determine the reasonable expectation of numbers of individuals. Data can be used to assess whether the standard or enhanced tier threshold has been met. The final reasonable assessment figure must also include staff. The responsible person should note that historic data is not always a reliable predictor of the future. Therefore, any assessment of historic data should be accompanied by regular and comprehensive review, to ensure that assumptions and circumstances remain valid.

Example 1: A nightclub establishes a safe occupancy figure of 875 individuals. However, the nightclub’s historic data over the last 12 months shows actual usage by visiting members of the public and staff has reached a maximum of 725 individuals during peak times such as seasonal periods, summer and Christmas.

Using this data, the nightclub can demonstrate that it meets the standard tier threshold as the number of individuals who might reasonably be expected to be at the nightclub at the same time did not exceed 725 (over the last year) and is not expected to do so during future usage. The nightclub should actively review this where numbers could feasibly be higher, for example, in advance of a themed night.

Example 2: A stately home opens its building and garden to the public. Visitors must purchase tickets before entry. The stately home’s visitor attendance records (historic data) show that over the last 12 months it has occasionally reached 850 visitors in a single day. However, those visitors do not stay all day and are not all present at the same time. The premises operator keeps an hourly count of visitors and assesses the average time a visitor stays (known as dwell time) to understand the maximum number of individuals on the premises at any one time for each hour of occupation.

Based on this assessment, the responsible person for the premises assesses that the maximum number of visitors at any one time is 300 individuals, and that it is reasonable to expect numbers will be the same or similar at the premises in future, from time to time. Therefore, the stately home is within the standard tier.

Example 3: The responsible person for a hotel has assessed that it is within the standard tier, based on the numbers it is reasonable to expect in its use as a hotel. The hotel holds an annual event on its land. There is a requirement to purchase a ticket prior to the event, which is checked on entry. The event organiser has never chosen to restrict numbers and therefore has not limited the number of tickets available for the event. The event is held annually, and historical data shows that there were 900 individuals at a single point during the event last year.

The hosting of the event every year indicates that the hotel qualifies as enhanced tier premises. This is because the frequency indicates that the 800 threshold is met from time to time, and the premises otherwise satisfy the criteria for qualifying premises in section 2 of the Act.

C: Fixed seating and / or fixed standing positions

16. Depending on the nature of the premises, the number of fixed seats and / or fixed standing positions can set or contribute to an assessment of the number of individuals that it is reasonable to expect. Staff must be included in the final reasonable assessment figure.

Example: A restaurant has indoor and outdoor dining areas. There is fixed seating for 450 individuals. It is also assessed that 30 staff will be working at any given time and the restaurant is full at peak times. It is therefore reasonable to expect 480 individuals at the premises at the same time. This figure represents the number of individuals at peak capacity. The restaurant is therefore within the standard tier.

D: Tickets and pre-registration

17. For premises or events that limit attendance based on the sale of tickets or pre‑registered attendees, the maximum number of tickets issued or those registered can be used to establish a reasonable expectation of the numbers of individuals who will attend. Staff must be included in the final reasonable assessment figure.

Example: A music event takes place in a large field. Members of the public must purchase a ticket prior to entry. A restriction of 300 is placed on the number of tickets issued at the same time via a pre‑sale. General sale follows, with a further 600 tickets purchased. Tickets are checked by security on entry.

The responsible person reasonably expects that 900 individuals would be present at the same time when the event is at full capacity. When staff are also included, the reasonable expectation of numbers increases by 300 individuals. The total number of individuals who are reasonably expected to attend at the same time at some point during the event is 1,200. This event is therefore a qualifying event and as such it must meet the enhanced duty requirements.

E: Restrictions

18. Premises and events that impose restrictions on attendance can use this figure to determine the number of individuals reasonably expected to be present (for example, a maximum attendance / capacity figure attached to an alcohol and entertainment licence).

Example 1: An event takes place in a museum which falls within the standard tier. Over the weekend, the museum operator allows an event organiser to use the museum to host a one-off exhibition. To maximise the visitor experience, they choose to stagger attendance using timed entry, noting what they expect to be the average attendance time for attendees. This means no more than 750 individuals are expected to be present at the exhibition at any one time.

The responsible person can use this restriction to demonstrate a reasonable expectation of no more than 750 individuals attending at the same time during the event. This means the event would not be a qualifying event in scope of enhanced tier requirements, but it would fall under the standard tier requirements of the museum.

Example 2: A nightclub operates under a licence which restricts the number of individuals permitted at the nightclub to 975 individuals. This upper limit to attendance is maintained on entrance and exit using a people counter clicker. The nightclub uses this licence figure to assess the reasonable expectation of individuals present and adds in the number of staff on duty. This figure places the nightclub in the enhanced tier.

F: Other means of assessing

19. There may be some circumstances in which the above methods (A to E) are not appropriate for various reasons, and using other methods may give a more accurate representation of the actual number of individuals reasonably expected to be present at the same time. For example, in some cases, the above methods may only be able to be used for some parts of the premises.

20. Where the above methods are not appropriate, other means of assessing the figure can be used together with a justification as to why using a different method is appropriate, how the figure has been calculated, and why the figure presents a reasonable assessment. As with the assessment methods listed above, this information (including assessment figures and underpinning assumptions) should be reviewed regularly to ensure the figure remains reasonable.

Calculations of numbers at different types of premises

21. Premises can be part of a building or a group of buildings. The calculation at such premises will be based on the number of individuals that it is reasonable to expect at the qualifying part of the building or the group of buildings.

Example 1: A building constitutes a large factory and a shop selling some of the produce it makes. The factory is a private workplace, which is not a qualifying Schedule 1 use. The shop’s use as a retail shop, however, is a Schedule 1 use. The shop assesses the numbers that it is reasonable to expect, including staff, to determine if it meets the 200 individuals (standard tier) or 800 individuals (enhanced tier) threshold.

Example 2: At a hospital complex there are 14 buildings. 13 buildings are under the direct control of the hospital trust. The other building contains a restaurant and shops which are leased to other operators by the hospital trust. The calculation of the number it is reasonable to expect for the premises must be based on all 14 buildings which form the premises as a group of buildings. In this instance, it is important that the building not under control of the hospital trust may also be a qualifying premises in its own right depending on whether it meets the scope criteria.

Footnotes

1. Terrorism (Protection of Premises) Act 2025 Statutory Guidance is available at: www.gov.uk/government/collections/terrorism-protection-of-premises-bill-2024 ↩

2.  Staff means all those working at the premises or event, including employees, contractors, volunteers and others. Staff may be full time, part time, shift workers or follow other working patterns. ↩

3.  Terrorism (Protection of Premises) Act 2025, Schedule 3, available at: www.legislation.gov.uk/ukpga/2025/10/schedule/3 ↩

4.   The Building Regulations 2010, Table of contents, available at: www.legislation.gov.uk/uksi/2010/2214/contents ↩