Commercial Fire Alarm Systems in London: What Every Business Owner Must Know

If you run a business in London, your fire alarm system is one of the most important pieces of equipment in the building. It is what gives your staff, customers and visitors the earliest possible warning to get out safely, and it is one of the first things a fire risk assessor, insurer or fire authority officer will ask about.

But buying a system is only the start. You also need the right type of system for your premises, a clear understanding of your legal duties, and a testing and servicing routine that keeps it dependable year after year.

This guide explains what every business owner and property manager should know about commercial fire alarm systems in London, written by the engineers at KForce Security.

Why Does Your Business Need a Commercial Fire Alarm System?

A fire can take hold in minutes. Without early warning, people may not realise anything is wrong until escape routes are already compromised.

A properly designed commercial fire alarm system helps you to:

• Detect fire at an early stage, often before anyone has noticed it
• Warn everyone in the building at the same time
• Support a calm, quick evacuation
• Reduce the risk of injury and loss of life
• Limit damage to your premises, stock and equipment
• Meet your legal duties and satisfy insurers

No two buildings carry the same risk. A small office, a restaurant kitchen, a warehouse and a multi-storey building all need different detection, which is why the system should always be designed around your premises, your occupancy and your fire risk assessment.

What Are Your Legal Responsibilities?

In England, the Regulatory Reform (Fire Safety) Order 2005 places fire safety duties on the Responsible Person. Depending on the premises, that may be the employer, business owner, landlord, managing agent or anyone else who has control of the building.

The Responsible Person must:

• Carry out a suitable and sufficient fire risk assessment and keep it under review
• Put in place the fire precautions that assessment identifies, which often includes a fire detection and alarm system
• Make sure fire safety equipment is properly maintained
• Provide staff with fire safety information and training
• Keep records of testing and maintenance

The Order does not say “install system X in building Y.” It requires you to provide precautions that are appropriate to your risks, which is why a professional site survey matters so much. Failure to comply can lead to enforcement notices, fines and, in serious cases, prosecution.

What Is BS 5839-1 and Why Does It Matter?

BS 5839-1 is the British Standard code of practice for the design, installation, commissioning and maintenance of fire detection and fire alarm systems in non-domestic premises. It is the benchmark that fire risk assessors, insurers and enforcing authorities expect commercial systems to follow.

The current edition is BS 5839-1:2025, which came into effect on 30 April 2025 and replaced the 2017 edition. Among other updates, it brings revised terminology, clearer system categories, more emphasis on competence and visual alarm devices, updated guidance on alarm signalling, and a more flexible approach to service intervals (covered below).

If your system was installed years ago, it may well have been designed to an earlier edition. That does not automatically make it non-compliant, but it is worth having it reviewed, especially if the building has changed since it was installed.

System Categories: L, P and M Explained

BS 5839-1 groups fire alarm systems by their purpose. Knowing these categories helps you understand what a quotation is actually offering.

Many commercial buildings combine life protection and property protection. The right category for your building should come from your fire risk assessment, not from a price list.

Types of Commercial Fire Alarm Systems

Conventional Fire Alarm Systems

A conventional system divides the building into zones. When a detector or call point activates, the control panel shows which zone the alarm is in, but not the individual device.

Conventional systems suit smaller premises where knowing the general area is enough, such as small offices, shops and compact commercial units.

Addressable Fire Alarm Systems

In an addressable system, every device has its own address. When one activates, the panel tells you exactly which detector or call point has triggered and where it is.

That precision makes a real difference in larger or more complex buildings, so addressable systems are the usual choice for hotels, schools, large offices, warehouses and multi-storey premises. They also make fault-finding quicker, which keeps maintenance costs down.

Wireless Fire Alarm Systems

Wireless systems use radio communication between devices and the control panel. They are ideal where running cable would be disruptive, costly or simply not possible, for example in listed or historic buildings, occupied premises during refurbishment, or buildings with awkward construction.

A wireless system still has to be properly designed, installed, commissioned and maintained to the same standards as a wired one.

Not sure which suits your building? Our guide to fire alarm types and our page on wireless fire alarm systems explain the options in more detail.

What Devices Make Up a Commercial Fire Alarm System?

• Fire alarm control panel: the brain of the system. It receives signals, processes alarms and displays faults and warnings.
• Smoke detectors: give early warning of smoke in offices, corridors, reception areas and other suitable locations.
• Heat detectors: respond to temperature, and are often better suited to kitchens, plant rooms and dusty or steamy areas where smoke detectors could cause unwanted alarms.
• Manual call points: let anyone raise the alarm by hand. They are sited along escape routes and at exits.
• Sounders: produce the audible alarm throughout the protected areas.
• Visual alarm devices: flashing beacons that warn people who may not hear an audible alarm. BS 5839-1:2025 places greater emphasis on these.
• Remote signalling (optional): connects the system to an alarm receiving centre so that the fire service can be called even when the building is empty.

How Often Should a Commercial Fire Alarm Be Tested and Serviced?

Weekly testing

BS 5839-1 recommends a weekly test carried out by the Responsible Person or a nominated person on site. A manual call point is operated, a different one each week so that every call point is tested in rotation over time. Check that the panel registers the alarm and that the sounders operate, then record the result in your fire alarm logbook.

If your system is monitored, tell your alarm receiving centre before you start so there is no unnecessary emergency response.

Professional servicing every six months

A competent fire alarm engineer should inspect and service the system at approximately six-month intervals. Under BS 5839-1:2025, a visit that falls anywhere from five to seven months after the previous one is acceptable, which gives businesses a bit of scheduling flexibility without letting the system go unchecked.

A service visit typically covers:

• Inspection of the control panel, including fault history and logbook review
• Testing of detectors, call points, sounders and visual alarm devices
• Battery and power supply checks
• Checks on any remote signalling or interfaces
• Checks for damage, contamination or building changes that affect coverage
• A written report, with any remedial work identified

Our separate guide covers this in more detail: How Often Does a Fire Alarm Need Testing According to BS 5839?

What to Do When Your Fire Alarm Shows a Fault

A fault warning on the panel should never be ignored. Common faults include:

• Low or failed standby batteries
• Detector faults
• Wiring and circuit faults, including earth faults
• Sounder circuit faults
• Communication or monitoring faults
• Control panel faults

Arrange for a competent engineer to investigate promptly. If part of the system is out of action, think about temporary fire safety measures, such as extra vigilance or a fire watch, until it has been restored, and make a note of the fault and the action taken in your logbook.

Remote Monitoring: Check Your Signalling Before It Becomes a Problem

If your alarm is connected to an alarm receiving centre over an analogue phone line, it is worth checking now. The UK’s telephone network is moving to digital (all-IP) technology, and BS 5839-1:2025 reflects this with updated expectations for alarm signalling. Systems that rely on older line-based signalling may need to be reviewed or upgraded so that alarm signals keep getting through.

Ask your fire alarm provider whether your signalling method will still work reliably as the phone network changes.

Why a Maintenance Contract Makes Sense

A planned maintenance contract takes the guesswork out of compliance. Instead of remembering when the next service is due, visits are scheduled for you, and the benefits add up:

• Regular professional inspections that catch developing faults early
• Fewer unwanted alarms and fewer disruptive call-outs
• A complete record of servicing for your logbook, insurer and fire risk assessor
• Clear recommendations for repairs or upgrades before problems become urgent
• Easier budgeting, especially for businesses with multiple sites

Find out more about our fire alarm maintenance and servicing.

When Should You Upgrade an Existing System?

Consider an upgrade if:

• The control panel is outdated or unreliable, or spare parts are hard to find
• You have repeated faults or frequent unwanted alarms
• The building has been extended, refurbished or changed use
• More people now occupy the building
• Your fire risk assessment has identified gaps in coverage
• Your alarm signalling still relies on an old analogue line

An upgrade does not always mean ripping everything out. Depending on its condition and compatibility, parts of an existing system can often be retained while the rest is replaced or extended. A survey will tell you what is worth keeping.

How to Choose a Commercial Fire Alarm Company in London

When comparing installers, look for:

• Third-party certification. BAFE certification shows a company has been independently assessed for fire safety work.
• Commercial experience. Ask about similar premises they have worked on.
• Knowledge of BS 5839-1:2025. Your installer should be working to the current standard.
• A proper survey. Be wary of quotes given without anyone visiting the building.
• Full documentation. You should receive commissioning certificates, zone plans and a logbook.
• Ongoing support. Make sure servicing, fault-finding and emergency repairs are available after installation.
• A clear written quotation setting out the equipment, the work and any exclusions.

Commercial Fire Alarm Installation and Maintenance with KForce Security

KForce Security is a BAFE-certified fire and security company based in Leytonstone, East London. We design, install, commission and maintain fire alarm systems for businesses, landlords and property managers across the capital, backed by 75+ five-star reviews and 1-2 hour emergency call-out response.

Our commercial fire alarm services include:

• New conventional, addressable and wireless fire alarm installations
• Six-monthly servicing and planned maintenance contracts
• Fault-finding and repairs
• System upgrades, extensions and modifications
• Detector and call point replacement
• Fire risk assessments and fire extinguisher servicing

We cover Leytonstone, Stratford, East Ham, Forest Gate, Walthamstow, Hackney, Ilford, Tottenham and the rest of London.

Take a look at our fire alarm installation in London service page, or see how a fire risk assessment can confirm what your building needs.

Frequently Asked Questions About Commercial Fire Alarm Systems

Do all commercial buildings need a fire alarm system? Not every building needs the same system, but most commercial premises need some form of fire detection and warning. What is appropriate depends on the building, how it is used and the findings of your fire risk assessment.

How often should a commercial fire alarm be serviced? Approximately every six months. Under BS 5839-1:2025, visits within a five-to-seven-month window are acceptable.

Is weekly fire alarm testing compulsory? Weekly testing is recommended by BS 5839-1 for non-domestic systems, and your duty under the Fire Safety Order is to keep the system properly maintained. In practice, fire risk assessors and insurers expect to see weekly tests recorded in your logbook.

Can I install a commercial fire alarm myself? No. Commercial systems must be designed, installed and commissioned by competent professionals. Mistakes can leave gaps in coverage or cause unreliable operation, and you would not be able to produce the certification that insurers and enforcing authorities expect.

What is the difference between a conventional and an addressable fire alarm? A conventional system tells you which zone an alarm is in. An addressable system identifies the exact device that has activated, which is faster and more precise in larger buildings.

Can my existing fire alarm be upgraded rather than replaced? Often, yes. After a survey, parts of an existing installation can usually be retained while the rest is upgraded or extended, depending on condition and compatibility.

How much does a commercial fire alarm system cost? It depends on the size and layout of the building, the type of system and the number of devices. We give a clear, itemised written quotation after a free site survey.

Book Your Free Fire Alarm Survey

Whether you need a brand new installation, a service for an existing system, or a second opinion on persistent faults, the KForce Security team is ready to help. We will visit your premises, tell you plainly what you need, and give you a written quotation with no obligation.

Looking for commercial fire alarm installation or maintenance in London?

📞 Call: 020 8638 6904 📧 Email: sales@kforcesecurity.co.uk 🔗 Book online: kforcesecurity.co.uk/contact-us/

KForce Security: BAFE certified fire and security systems. 724 High Road, Leytonstone, London E11 3AJ.