How Many First Aiders Does a Workplace Need?
How many first aiders a workplace needs depends on two things: the level of risk and the number of people on site. A low-risk office with a handful of staff may need only one, while a busy construction site needs several trained on the full First Aid at Work course. The simplest way to meet the requirement is to carry out a needs assessment and then book a first aid course for the right number of people.
This guide sets out how many first aiders you need by risk level, explains who actually counts as a qualified first aider, and shows how to get your team trained without leaving a gap in cover.
How Many First Aiders You Need by Risk Level
There is no single fixed number that applies to every workplace. Instead, HSE guidance gives suggested numbers based on how hazardous the work is and how many employees are present. Working out how many first aiders you need starts with deciding whether your workplace is lower risk or higher risk, then matching the headcount to the guidance below.
| Workplace risk | Number of employees | Suggested first aid provision |
|---|---|---|
| Lower risk (offices, shops) | Fewer than 25 | At least one appointed person |
| Lower risk | 25 to 50 | At least one first aider trained in EFAW |
| Lower risk | More than 50 | At least one First Aid at Work first aider per 100 staff |
| Higher risk (construction, engineering) | Fewer than 5 | At least one appointed person |
| Higher risk | 5 to 50 | At least one first aider trained in EFAW or First Aid at Work |
| Higher risk | More than 50 | At least one First Aid at Work first aider per 50 staff |
These are suggested numbers, not a rigid legal quota. When you decide how many first aiders you need, you should also allow for cover during holidays, sickness and shift work, so the workplace is never left without a qualified first aider on duty.
Low-Risk vs High-Risk Workplaces
The difference in risk level is the biggest factor in how many first aiders you need. A higher-risk workplace such as a construction site has more ways for serious injury to happen, so it needs more first aiders and they should hold the full First Aid at Work qualification rather than the one-day EFAW.
A lower-risk workplace such as a small office has fewer hazards, so the guidance suggests fewer first aiders, and a basic EFAW qualification may be enough for smaller teams. The key point is that the number and the level of training both rise as risk rises.
Who Counts as a Qualified First Aider
Only someone holding a current, valid certificate counts towards how many first aiders your workplace has. An appointed person who takes charge of arrangements but has no qualification does not count as a first aider. Neither does someone whose certificate has expired.
This is why tracking certificate expiry dates matters. If a first aider leaves or their certificate lapses, your headcount of qualified first aiders drops, and you may fall below the number your risk assessment requires. Keeping a simple record of who is trained and when each certificate expires keeps you compliant.
How to Get Your Team Trained
Once you know how many first aiders you need, the next step is to book them onto a course. For higher-risk workplaces, that means the full First Aid at Work qualification. Knight Learning delivers this first aid training in person at its London centre over two days, with a weekend option available, and issues a certificate valid for three years.
Training more than one person is sensible even if the guidance suggests a single first aider, because it gives you cover for absence and shift patterns. Planning ahead also means you can stagger renewals so you never lose too many qualified first aiders at once.
Frequently Asked Questions
There is no single legal number. The law requires adequate provision based on a first aid needs assessment. HSE guidance gives suggested numbers by risk level and headcount, which most employers use as their benchmark.
Construction is higher risk, so the guidance suggests at least one appointed person for very small sites and at least one First Aid at Work first aider for every 50 staff once you pass 50 employees. Most sites train several first aiders to cover shifts and absence.
No. An appointed person manages first aid arrangements but is not a trained first aider. Only someone with a current, valid certificate counts towards how many first aiders your workplace has.
Higher-risk workplaces need first aiders trained on the full First Aid at Work course. Lower-risk workplaces may be covered by the one-day Emergency First Aid at Work qualification.
Every three years, as that is how long a certificate lasts. Renewing before expiry keeps your number of qualified first aiders stable and avoids retaking the full course.
