Most businesses need some way of warning everyone if there's a fire. In a small shop that might be a simple manual system; in a hotel or care home it means automatic detection throughout. Your fire risk assessment decides what's right.

What the Law Says

Fire safety law across the UK requires suitable fire detection and warning, based on your fire risk assessment, and requires it to be maintained. The British Standard for business fire alarm systems is BS 5839-1:2025, which replaced the 2017 edition. It's a recommendation, but it's the accepted benchmark.

System Categories

  • M – manual only: break-glass call points and sounders.
  • L1–L5 – automatic detection to protect life. L1 covers the whole building; L4 covers escape routes only; L2 and L3 sit in between; L5 is designed for a specific purpose.
  • P1 and P2 – automatic detection to protect property, throughout (P1) or in defined areas (P2).

The Main Parts

  • Manual call points – "break glass" units to raise the alarm.
  • Detectors – smoke, heat or multi-sensor.
  • Sounders – bells, sirens or voice sounders, which play a recorded spoken message telling people to leave. Larger buildings may have a full voice alarm system, covered by BS 5839-8.
  • Visual alarm devices – flashing beacons for people who are deaf or hard of hearing, and for noisy areas.
  • Control panel – shows where the alarm was raised.

Wireless (radio-linked) systems are useful in listed buildings and where cabling is difficult.

Conventional or Addressable?

Business fire alarm systems come in two main types:

  • Conventional – detectors and call points are wired in groups called zones, such as one zone per floor or area. The control panel shows which zone the alarm came from, but not the exact device, so someone has to search that zone to find the fire. They cost less and suit smaller, simpler buildings with only a few zones.
  • Addressable – every detector and call point has its own address, so the panel shows exactly which one has gone off – for example, "smoke detector, room 12, first floor". That means the fire can be found faster, and faults and false alarms are easier to track down. They cost more to buy but suit larger or more complex buildings, and premises such as care homes where staff need to know exactly where the fire is.

Your fire alarm engineer will advise which type suits your premises.

Alerting Deaf and Hard of Hearing People

A sounder alone won't warn everyone. Your fire risk assessment needs to consider how deaf and hard of hearing staff, visitors and guests will know the alarm has gone off:

  • Visual alarm devices – flashing beacons, especially in toilets, quiet rooms and anywhere someone might be alone. They won't wake someone who's asleep.
  • Vibrating pagers – carried by staff or visitors and linked to the fire alarm, so they vibrate (and often flash) when it goes off, wherever the person is in the building.
  • Vibrating pillow pads – for hotels and anywhere people sleep. A pad under the pillow, often part of a portable kit with a flashing beacon, wakes the guest when the alarm sounds. Hotels can issue these kits at check-in, so ask guests if they need one.
  • A plan for the person – a personal emergency evacuation plan (PEEP), and a colleague or member of staff who will make sure they've been alerted. See Fire Drills and Evacuation Plans.

Testing and Servicing

  • Weekly – test the alarm at the same time each week, using a different call point each time, and record it.
  • Every six months – servicing by a competent person.
  • Log book – keep one by the panel, in a fire safety document holder or cabinet. See Fire Safety Log Books: What to Record.

Look for a company certified under a third-party scheme such as BAFE (British Approvals for Fire Equipment) SP203-1 – a good sign of competence. Make sure their BAFE certification is for fire alarms – SP203-1 – and not just for another service, such as extinguisher servicing (SP101) or fire risk assessments (SP205). You can check on the BAFE register.

False Alarms

Many fire and rescue services no longer send fire engines to automatic alarms from many non-residential buildings unless a fire is confirmed – for example, the Scottish Fire and Rescue Service at any time, and London Fire Brigade during the day. Check your local service's policy, and investigate every false alarm.

Building Sites and Homes

Construction sites need an alarm everyone can hear – often a temporary wireless site alarm. Homes use smaller systems under BS 5839-6 – see Smoke, Heat and Carbon Monoxide Alarms.

Worth remembering… your fire risk assessment is what decides what your premises need. This guide is general advice, not a substitute for it.

Not sure what you need? Get in touch with our team – we'll be delighted to help. No pressure. No sales patter.