Is It a Legal Requirement to Have a Fire Alarm in a Commercial Property?

Yes, in practice. UK fire safety law requires every commercial property to have a suitable way to detect a fire and warn everyone inside. The law does not name one specific system for every building. Instead, your fire risk assessment decides what is “appropriate”, and for almost every business with more than a single small room, that means an electrical fire alarm system.

If your fire risk assessment shows you need a system, commercial fire alarm installation from Platinum Asset Protection covers design, supply, installation and maintenance, and it sits alongside our wider site security solutions so one team protects your premises from fire, theft and intrusion.

Below is exactly what the law says, who is responsible, what kind of system you need and what happens if you get it wrong.

What the Law Actually Says

Fire safety in non-domestic premises is covered by different legislation in each part of the UK, but the duty is the same everywhere: assess the fire risk and provide fire detection and warning where it is needed.

Nation

Main legislation

England and Wales

Regulatory Reform (Fire Safety) Order 2005, amended by the Fire Safety Act 2021 and the Building Safety Act 2022

Scotland

Fire (Scotland) Act 2005 and the Fire Safety (Scotland) Regulations 2006

Northern Ireland

Fire and Rescue Services (Northern Ireland) Order 2006 and the Fire Safety Regulations (Northern Ireland) 2010

In England and Wales, the Fire Safety Order requires the responsible person to make sure premises are equipped with appropriate fire detectors and alarms where necessary. The word “necessary” is decided by the fire risk assessment, not by guesswork.

The Fire Safety Order applies to all non-domestic premises and to the communal parts of residential buildings, such as the stairwells and corridors of a block of flats.

Construction sites have their own rule

Construction sites are covered by the Construction (Design and Management) Regulations 2015. Regulation 32 says that, where necessary for the health or safety of people on site, suitable fire detection and alarm systems must be provided, and they must be examined, tested and maintained at suitable intervals. Temporary site buildings, welfare cabins and partly built structures all fall within this.

New buildings and major alterations

When a commercial building is built or materially altered, Building Regulations also apply. In England this is covered by Approved Document B, which sets out when fire detection and alarm systems must be designed into the building from the start.

So Does Every Commercial Property Need a Fire Alarm System?

Not every property needs a complex, networked system, but every property needs an effective warning. The test is simple: when a fire starts anywhere in the building, will everyone hear the warning in time to get out safely?

A very small, single-room, open-plan shop might meet that test with a shouted warning or a manual device, because everyone can see and hear everyone else. As soon as you have separate rooms, more than one floor, storage areas, people working alone, members of the public, or anyone sleeping on the premises, a shout is no longer reliable. At that point an electrical fire alarm system is effectively the only way to comply.

Premises where a proper system is almost always required include:

  • Offices across more than one room or floor
  • Warehouses, distribution centres and industrial units
  • Retail premises with stockrooms or upper floors
  • Hotels, care homes and any premises where people sleep
  • Restaurants, pubs and venues open to the public
  • Communal areas of flats and mixed-use buildings

Who Is Legally Responsible?

The law places the duty on the “responsible person”. This is usually the employer, but it can also be the owner, landlord, occupier or managing agent, depending on who controls the premises. In shared or multi-let buildings there can be more than one responsible person, and they are legally required to cooperate and coordinate.

The responsible person must:

  1. Carry out a fire risk assessment and review it regularly
  2. Put the right fire safety measures in place, including detection and warning
  3. Keep the fire alarm and other fire safety equipment maintained and in working order
  4. Plan for emergencies and make sure staff know what to do
  5. Provide fire safety information and training to staff

The written record rule changed in 2023

Since 1 October 2023, section 156 of the Building Safety Act 2022 requires the responsible person in England to record the fire risk assessment and the fire safety arrangements in full, regardless of the size or type of business. The old exemption for businesses with fewer than five employees no longer applies.

What Type of Fire Alarm System Do You Need?

The law sets the duty. The British Standard sets the detail. BS 5839-1 is the code of practice for fire detection and fire alarm systems in non-domestic buildings. The current edition, BS 5839-1:2025, came into effect on 30 April 2025 and replaced the 2017 version.

BS 5839-1 is not law in itself, but fire and rescue services, building control and insurers all use it to judge whether a system is suitable. Following it is the clearest way to show you have met your legal duty.

The standard groups systems into categories:

Category

Purpose

Typical use

M

Manual only: break glass call points and sounders, no automatic detection

Small, low-risk premises where people are always present and awake

L1 to L5

Life protection: automatic detection to give early warning so people can escape

Offices, retail, hotels, care homes, multi-occupied buildings

P1 and P2

Property protection: detection to alert the fire service early and limit damage

Warehouses, stock-heavy premises, buildings that are empty out of hours

Many businesses need a combination, for example an L category to protect staff during the day and a P category to protect stock and buildings overnight. Your fire risk assessment should state the category required.

A typical commercial system includes smoke, heat or multi-sensor detectors, manual call points, sounders and visual beacons, and a control panel. Smaller sites often use a conventional panel, while larger or more complex buildings benefit from an addressable panel that pinpoints exactly which device has triggered.

For larger or higher-risk premises, commercial fire detection systems can be combined with thermal security cameras, which detect rising temperatures in open yards, stock areas and plant rooms where standard detectors are less effective.

Testing and Maintenance: The Part Most Businesses Get Wrong

Installing an alarm is only half the duty. The law also requires it to be kept in efficient working order. BS 5839-1 recommends:

  • Weekly: a test of the system using a different manual call point each week, recorded in the logbook
  • Every six months at most: inspection and servicing by a competent person
  • Every time: a logbook entry for tests, faults, false alarms and any changes to the system

An alarm that has not been tested or serviced may fail when it matters, and it will not satisfy an enforcing officer or an insurer after an incident.

What Happens If You Do Not Comply?

Fire safety law is enforced by the local fire and rescue service. Their officers can inspect premises and take action where they find serious risks.

  • Enforcement notices requiring improvements by a set date
  • Prohibition notices restricting or stopping use of the premises until the risk is fixed
  • Prosecution, with unlimited fines and, for the most serious breaches, up to two years in prison

Beyond the legal penalties, a missing or poorly maintained fire alarm can affect your insurance cover and, most importantly, put lives at risk.

Fire Alarms for Construction Sites, Warehouses and Empty Buildings

Some premises carry higher fire risks and need particular attention.

Construction sites change every week. Hot works, temporary power, stored materials and site cabins all raise the risk, and CDM 2015 requires detection and alarms to keep pace with the build. Fire protection works best as part of wider construction site security services, where monitoring also covers arson and out-of-hours activity.

Warehouses hold large volumes of stock and packaging in high, open spaces, which allows fire to spread quickly. Property protection categories, combined with warehouse security solutions, protect both people and stock.

Vacant buildings are still covered by fire safety law and are common targets for arson. Vacant property security keeps the building monitored while it sits empty.

Quick Compliance Checklist

  1. Is your fire risk assessment up to date and recorded in full?
  2. Does it state what fire detection and warning your premises need?
  3. Is your fire alarm the right category for how the building is used?
  4. Is the system tested weekly and serviced at least every six months?
  5. Is there a logbook recording tests, faults and false alarms?
  6. Have you reviewed the system after any change to layout, use or occupancy?

Frequently Asked Questions

The law requires every business to have an effective way to warn people of fire. A very small, single-room business may manage without an electrical system if everyone can hear a shouted warning, but most businesses need one. Your fire risk assessment decides.

The responsible person is whoever controls the premises. This is often the tenant for their own unit and the landlord for shared areas. Your lease should make this clear, and both parties must cooperate.

No. It is a code of practice, not law. However, enforcing authorities and insurers use it as the benchmark for a suitable system, so following it is the most reliable way to show compliance.

BS 5839-1 recommends a weekly user test and inspection and servicing by a competent person at intervals of no more than six months.

Yes, where necessary for the health or safety of people on site. CDM 2015 Regulation 32 requires suitable fire detection and alarm systems, tested and maintained at suitable intervals.

Enforcement or prohibition notices, and for serious breaches, prosecution with unlimited fines and up to two years in prison.

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