Fire alarm systems: an overview
Fire alarm systems provide warning when fire is detected or reported. The appropriate arrangement depends on the building, people at risk, evacuation strategy and fire risk assessment.
Reviewed: 20 August 2026
This guidance is general information. The correct fire safety measures depend on the premises, its use, occupants, fire risk assessment and applicable legal duties.
What a fire alarm system is expected to achieve
A fire warning arrangement should provide a suitable means of alerting people so they can respond to a fire. Simple premises can differ substantially from sleeping, complex or higher-risk premises.
Fire safety law does not prescribe one universal system for every building. The responsible person must provide and maintain appropriate precautions based on risk.
Domestic and non-domestic standards
BS 5839-1:2025 is the current BSI code of practice for fire detection and alarm systems in non-domestic premises. BS 5839-6:2019+A1:2020 is listed by BSI as current for domestic premises.
Testing and maintenance
Government fire safety guidance recommends regular testing and maintenance. For many non-domestic systems, weekly user testing forms part of the routine management regime, while periodic servicing is carried out by a competent person.
Records to retain
A useful property record links installation and commissioning certificates, service records, zone information, weekly tests, faults, false alarms, repairs and later alterations.
- Installation or commissioning certificate
- Periodic inspection and servicing certificate
- Zone plan and system information
- Weekly test log
- Fault, repair and alteration history
Frequently asked questions
Does every business need an automatic fire alarm system?
Not necessarily. The fire risk assessment determines the appropriate means of detection and warning for the premises.
Which British Standard covers non-domestic fire alarms?
BS 5839-1:2025 is the current BSI code of practice for non-domestic premises.
Should fire alarm testing be recorded?
Yes. Government guidance recommends suitable records of testing and maintenance.
Sources and further reading
For legal duties and technical standards, use the current primary source and professional advice where required.