BS 5839-1: fire alarm systems in non-domestic buildings, explained
Reviewed by the SPS Technical team · Last checked 12 October 2026
Quick answer
BS 5839-1 is the British Standard code of practice for designing, installing, commissioning and maintaining fire alarm systems in non-domestic buildings. It recommends a service by a competent person at least every six months, a weekly user test and a logbook kept on site. The current edition is BS 5839-1:2025.
What it means for you
- Have your system serviced by a competent person at least every six months.
- Test one manual call point every week, a different one each time, and record it.
- Keep a logbook of tests, faults, false alarms and service visits.
- Investigate false alarms and fix the cause rather than resetting and moving on.
- Get design, installation and commissioning certificates for new systems and changes.
Who it applies to
Offices, shops, schools, factories, warehouses, hospitals and other non-domestic premises. Homes and the dwellings in blocks of flats are covered by BS 5839-6 instead. The Fire Safety Order 2005 makes the Responsible Person accountable for keeping the system maintained, and following BS 5839-1 is the recognised way to show that.
What changed from BS 5839-1:2017
The 2025 edition adds a section on modifying or extending existing systems, tightens the limits on agreed variations, simplifies the rules on where manual call points go, favours smoke detection over heat detection in sleeping areas such as hotels, care homes and student accommodation, and is restructured to make it easier to use.
Common questions
How often does BS 5839-1 say a fire alarm should be serviced?
At least every six months, by a competent person. Higher-risk sites, or systems with frequent false alarms, may need more frequent visits.
Is BS 5839-1 a legal requirement?
The standard itself is not law, but the Fire Safety Order 2005 requires fire safety systems to be maintained. Following BS 5839-1 is the recognised way to show you have met that duty, and insurers and fire services expect it.
Who can service a fire alarm?
A competent person. Third-party certification such as BAFE SP203-1 is the clearest way to show a company is competent.
What is the difference between the weekly test and a service?
The weekly test is a quick check you do yourself, setting off one call point to make sure the alarm sounds. A service is a full inspection by a competent engineer, covering the panel, batteries, detectors and records.
Does my existing system need upgrading because of the 2025 edition?
Not automatically. A new edition applies to new work and changes. At each service your engineer should flag anything that no longer meets the standard so you can plan any work with your fire risk assessment.
Official sources
- BS 5839-1:2025 on BSI Knowledge
- BSI: a guide to the changes in BS 5839-1
- FIA guide to the changes in BS 5839-1:2025 (PDF)
- Regulatory Reform (Fire Safety) Order 2005
This page is a plain-English summary, not a copy of the standard. British Standards are copyright of BSI.
Page updates
- 12 October 2026: Edition updated to BS 5839-1:2025, which replaced BS 5839-1:2017 on 30 April 2025.
Reviewed by the SPS Technical team · Last updated October 2026