How to Work Out Your 'Reasonably Expected' Numbers for Martyn's Law

Everything Martyn's Law asks of your premises begins with one figure: the number of people who can reasonably be expected on site at the same time. Knowing how to count people for Martyn's Law comes down to choosing a sound method and supporting it with evidence. The Home Office sets out acceptable approaches in Supplementary Document A, and the Security Industry Authority can ask a responsible person to explain how they carried out an assessment.

What "Reasonably Expected" Means in Practice

The assessment looks at how many individuals may be on the premises together at one moment, from time to time. "At the same time" means simultaneous presence. "From time to time" means occasionally, so a figure reached only on certain nights or at certain times of year still counts. The guidance gives the example of a major televised sports event lifting attendance at a pub. Where similar crowds can reasonably be expected again, that level applies. Daily or weekly averages carry no weight, and a one-off surge nobody could have anticipated sits outside the picture.

You may also see this called Martyn's Law tiers guide. The Home Office now describes it as an assessment of the number of individuals expected to be present, and the reasonably expected number for Martyn's Law can come in lower than your safe occupancy figure.

Six Methods the Home Office Lists for Reaching Your Figure

The guidance offers non-exhaustive examples and leaves room for judgement. Whichever you choose, the final number includes staff:

• Safe occupancy for fire safety: the maximum number the building can accommodate.
• Historic attendance data: records from previous years that reflect actual peak use.
• Fixed seating or standing positions: the count of seats or set positions.
• Tickets and pre-registration: the maximum tickets issued or registrations accepted sets an upper limit.
• Restrictions: a cap attached to something like an alcohol and entertainment licence.
• Other means: any alternative method, backed by a justification and supporting evidence.

Martyn's Law: How to Count People Using Historic Data and Live Counts

Peak-hour records show how many people are on site at once, which can be well below the total who pass through in a day. The guidance describes a stately home that reached 850 visitors in a single day. Visitors arrived and left at different times, so the operator kept an hourly count, worked out the average dwell time, and found that no more than 300 were present at once. A nightclub with a safe occupancy figure of 875 used 12 months of records showing a peak of 725 during busy seasonal periods.

Everyday sources can supply the same kind of evidence:

• Footfall counters that log entries and exits by the hour.
• Front-desk or reception logs recording arrival and departure times.
• Ticket scans that show how many people are inside at any moment.
• Clicker counts at entrances, as the guidance describes for a licensed nightclub.

Historic data is not always a reliable predictor, so the guidance advises regular review, for instance ahead of a themed night when numbers could run higher.

Who and What Belongs in the Count

Staff and areas both shape the final number. These points apply:

1. Staff working at the premises count, including employees, contractors and volunteers.
2. Only people in the part of the premises used for a qualifying purpose are included.
3. Outdoor seating that fills regularly adds to the total. A café with a fire safety figure of 180 and 30 outdoor seats reaches 210.
4. Premises made up of several buildings are assessed across the whole group.
5. The immediate vicinity, such as the pavement outside, need not be counted.

Record the Figure, the Evidence and a Review Trigger

Once you have a peak concurrent number, add the staff expected on shift and write down the method, the date range of data reviewed, the assumptions made and who signed it off. The SIA can request this information under Schedule 3 of the Act, so a tidy record saves time later. Set a review whenever circumstances change, such as a restaurant growing busier at peak times after strong reviews.

A Documented Peak Figure Gives You Evidence You Can Stand Behind

Start with your fire safety occupancy figure, test it against real attendance data, add staff, and keep a dated record. Most premises already hold the ticketing exports, logs and counters needed for a confident assessment. If you are unsure where to start, talk to us and we will help you work out your first steps.

Expert FAQ

How do I work out the reasonably expected number for Martyn's Law?
Pick a suitable method, such as fire safety occupancy or historic peak data, then add staff to reach your figure.

What does "from time to time" mean under Martyn's Law?
It means occasionally. Peaks on certain nights or seasons count when similar attendance can reasonably be expected again.

Why must staff be included in the count?
The guidance requires all individuals present to be counted, including staff working in the qualifying part of the premises.

How often should I review my assessment?
Review it regularly and whenever circumstances change, such as a venue becoming busier at peak times after positive reviews.

What evidence should I keep to support my figure?
Keep the method used, data date range, assumptions, staff numbers, and sign-off, since the SIA can request this information.

Disclaimer: This article provides general information only and does not constitute legal advice. Martyn’s Law requirements and official guidance may change, and every premises is different. For advice on your specific circumstances, consult a qualified legal professional and refer to the latest Home Office and Security Industry Authority guidance.