How often should commercial fire alarms be serviced?

The short answer

At least twice in any twelve-month period, with no more than six months between visits. That is the recommendation in BS 5839-1, the code of practice for fire detection and alarm systems in non-domestic premises. Higher-risk or larger systems are commonly serviced quarterly.

Separately, the standard expects a weekly user test carried out by someone on site — operating a different manual call point each week and recording the result in the logbook. That is not a contractor visit and it does not replace servicing.

Where the legal duty actually sits

This is worth being precise about, because a lot of contractors are not.

BS 5839-1 is a British Standard, not a statute. Nobody is prosecuted for departing from it. What creates the legal duty is Article 17 of the Regulatory Reform (Fire Safety) Order 2005, which requires that fire safety equipment is subject to a suitable system of maintenance and is kept in efficient working order and in good repair.

The standard is how you demonstrate you have met that duty. Enforcing authorities, insurers and courts all treat servicing to BS 5839-1 as the recognised benchmark, so departing from it puts you in the position of having to justify why. That is a perfectly legitimate thing to do — a small, simple system in a low-risk building may not need quarterly attendance — but it should be a recorded decision arising from your fire risk assessment, not an accident of whoever you happened to appoint.

What a service visit should actually include

A visit that consists of putting the panel into test, walking round with a smoke tester and signing a docket is not a service. The standard's schedule covers:

• Examination of the logbook, and a review of every event and fault recorded since the last visit
• Control panel inspection, including indicators, controls and any faults standing
• Testing of a proportion of detectors and all manual call points across the service cycle, arranged so that every device is tested at least annually
• Sounder and visual alarm device verification, including sound pressure levels where there is any doubt about audibility
• Standby power supply testing — batteries are the most common cause of a system failing when it is actually needed
• Interface and cause-and-effect verification wherever the system controls door holders, lifts, air handling, gas shut-off or smoke ventilation
• A written service certificate and a logbook entry

The part most contracts get wrong

Defects. An engineer finds three faults, mentions them to whoever is on reception, and leaves. Six months later the same three faults are still there, and the file contains two certificates saying the system was serviced.

A service certificate that lists unresolved defects is evidence that you knew about a problem and did not fix it. That is a worse position than not having had the service at all. Whatever contractor you use, the test of the arrangement is not whether they attend — it is whether defects get closed and evidenced.

What about domestic and residential systems?

Different standard. BS 5839-6 covers fire detection in domestic premises, including individual flats and houses in multiple occupation, and it uses grades and LD categories rather than the L and P categories used in non-domestic buildings. Communal systems in a residential block are usually designed to BS 5839-1, while the detection inside each dwelling falls under BS 5839-6 — so one building can legitimately sit under both.

And fire doors, extinguishers and emergency lighting?

Each has its own interval, and they do not align, which is why compliance calendars drift:

• Emergency lighting — a monthly short function test and an annual full rated duration test, under BS 5266-1
• Fire extinguishers — an annual basic service under BS 5306-3, with extended service or overhaul at longer intervals depending on type
• Fire doors — in England, in multi-occupied residential buildings over 11 metres, quarterly checks of communal fire doors and annual checks of flat entrance doors under the Fire Safety (England) Regulations 2022

The practical answer for most organisations is to hold them on a single calendar with one provider, so that six separate expiry dates do not become six separate opportunities to forget.