How Often Should a Commercial Intruder Alarm Be Serviced?

Key takeaway

Most monitored commercial intruder alarms should be serviced twice in every 12-month period. An audible-only system is generally checked once a year, but the correct interval depends on the alarm grade, monitoring arrangement, manufacturer, insurer, police response conditions and risk at the premises. Repeated false alarms, low batteries, signalling faults, building changes or missing records are reasons to arrange an earlier review.

Most monitored commercial intruder alarms should be serviced twice a year. An audible-only alarm is generally checked once a year. That is a useful starting point, not a universal legal rule: your insurer, alarm grade, manufacturer, monitoring contract, police response conditions and the risks at the premises may require a different interval.

A service visit is more than testing whether the siren sounds. It should confirm that the detectors, door contacts, control panel, batteries, signalling path, keyholder details and records still work together as one security response. If the system is connected to an Alarm Receiving Centre, often called an ARC, the test should include the signals that the ARC is expected to receive.

Is twice-yearly servicing a legal requirement?

There is not one single UK law that sets the same service interval for every intruder alarm in every business. The interval comes from the combination of the system design, the relevant standards and guidance, the monitoring arrangement, the insurer's conditions, the police response policy and the agreement with the maintenance provider.

The National Security Inspectorate says an audible-only alarm should be checked once a year, while a system that signals to an approved ARC should be serviced or maintained twice a year. That guidance reflects the greater reliance placed on a remotely monitored system, especially when the premises are empty.

If your insurance schedule or monitoring agreement specifies a shorter interval, follow that requirement. Keep the service reports with the alarm logbook and make sure the next visit is booked before the existing agreement expires.

How often should a monitored business alarm be serviced?

A sensible baseline is every six months. A monitored system has more parts that can affect the response: the alarm panel, detection devices, power supply, standby batteries, external sounder, telephone or IP communicator, mobile path, ARC account and nominated keyholders.

Six-monthly visits also give a business a regular opportunity to review false alarms and changes around the building. A new partition, dusty work area, changed stock layout, new roller shutter or altered access route can affect how the alarm performs even when no component has failed.

The engineer should leave a dated service report that records the system condition, tests completed, faults found, remedial work recommended and any signals confirmed with the ARC. A report that only says "tested OK" gives a facilities manager very little evidence to rely on later.

What changes the recommended service interval?

The twice-yearly baseline may not be enough for every site. Ask for a risk review if any of the following apply:

• Higher security risk: the premises hold valuable stock, sensitive information, cash, controlled goods or equipment that would be difficult to replace.
• Frequent false alarms: repeated activations can lead to lost confidence, unnecessary callouts and a review of police response eligibility.
• Harsh conditions: dust, vibration, temperature changes, condensation or outdoor exposure can shorten the useful life of detectors and contacts.
• Heavy use: busy doors, loading bays, staff entrances and shared buildings can put more wear on contacts, locks and user equipment.
• Insurance conditions: the policy may require a recognised installer, a maintenance contract, specific alarm grading or documented service visits.
• Police response: a system seeking a police response must follow the current NPCC and local force requirements, including approved installation, monitoring and false-alarm management.
• Recent changes: building work, a new tenant, a change of use, extra doors or a new keyholding arrangement can make the old design or records incomplete.

Do not reduce the frequency simply because the alarm has not activated. A quiet event log proves very little if a detector, battery or communication path has not been tested properly.

What should a commercial intruder alarm service include?

The exact checks depend on the system and its grade, but a competent visit should normally cover the following areas:

1. Control panel and user equipment: check the panel, keypads, indicators, user codes, time settings, event log and tamper condition.
2. Detection devices: test movement detectors, door contacts, shock sensors, glass-break devices, external detectors and any specialist protection.
3. Sounders and visual indicators: confirm that the external and internal warning devices operate and remain securely fixed.
4. Power and batteries: inspect the mains supply, standby battery condition, charging and low-voltage reporting. Batteries should be replaced before failure creates a gap in protection.
5. Signalling: test the agreed alarm, fault, mains-fail and communication-failure signals with the ARC or monitoring provider.
6. False-alarm controls: review recent activations, identify likely causes and recommend a repair, adjustment, user change or design review where needed.
7. Site condition: check for blocked detectors, changed room layouts, damaged cables, new doors, building work or other changes that affect coverage.
8. Records and response: confirm the premises details, keyholders, passwords, access arrangements, emergency number and service history.

Testing should be planned with the business so staff know when the system is in test mode. The engineer should explain any temporary isolation and confirm when full protection and monitoring have been restored.

What should staff check between service visits?

Routine user checks do not replace professional maintenance. They help a business spot a problem early and keep the response plan usable.

• Check the panel for fault, tamper, low-battery or communication warnings.
• Make sure detectors and contacts have not been covered, moved or damaged.
• Keep alarm logbook entries up to date after tests, activations and faults.
• Tell the alarm company about building work, new doors, changes of use and equipment moved near detectors.
• Check that at least two suitable keyholders remain contactable and able to attend.
• Use the agreed process for setting and unsetting the system, including the out-of-hours procedure.

Police.uk advises businesses to keep a monitored alarm fully operational, while ProtectUK explains that keyholders should understand the controls, be contactable and be able to attend the premises. Treat those arrangements as part of the security system, not as an admin detail.

When should an alarm be serviced sooner?

Book an earlier visit if the alarm shows a fault, the battery warning returns, the ARC reports a communication problem or the system activates without an obvious cause. Do the same after a break-in, attempted break-in, water leak, power problem, lightning event or damage to a sensor or cable.

An earlier review is also sensible before an insurance renewal, a premises handover or a major refurbishment. If you have inherited an alarm with no clear service history, ask for a system takeover inspection before assuming that the equipment and records are suitable.

Can a business service its own intruder alarm?

Staff can carry out agreed user tests and report visible faults, but professional servicing should be completed by a competent alarm specialist. A service visit may involve opening equipment, checking batteries and signalling, testing devices individually and coordinating with an ARC. An unplanned test can also create a false alarm or leave part of the system bypassed.

If police response or insurance cover matters, check whether the installation and maintenance company needs approval from a recognised inspectorate. NSI explains that approved installers can assess the premises, design a system to the relevant requirements and provide maintenance and ARC arrangements. Ask the installer to show the approval that applies to the work instead of relying on a generic claim of accreditation.

What happens if the system has repeated false alarms?

Do not simply silence the siren or disconnect the troublesome detector. Record the activation, identify the likely cause and ask the maintainer to investigate. Steam, dust, insects, unstable doors, poor detector placement, user error and failing batteries can all create nuisance alarms, but the correct remedy depends on the site.

Police response policies can withdraw or downgrade response after repeated false alarm calls. NSI notes a three-false-alarm threshold for immediate response in England, Wales and Northern Ireland, subject to the current policy. The exact process, reinstatement conditions and local arrangements should be checked with the relevant force and ARC.

A good maintenance report should explain what caused the alarm, what was changed and how the system was tested afterwards. If the same device keeps triggering, the issue may be the environment or the design rather than staff behaviour.

What about old telephone-line signalling?

Check the communication path as carefully as the detectors. A panel can appear normal while its old telephone, mobile or single-path communicator is no longer suitable for the way the business needs to be protected.

Ask the maintainer what happens if the primary path fails, whether the ARC receives a communication fault and whether the system uses a resilient route. If the alarm still relies on a legacy phone-line arrangement, read FIDEC's intruder alarm future-proofing guide and arrange a signalling review before the PSTN retirement affects the site.

Questions to ask before agreeing an alarm maintenance contract

• How many planned service visits are included each year?
• Does the price include ARC signal testing, batteries and a written service report?
• What is the response time for a fault or an alarm activation?
• Who can carry out remedial work, and how will chargeable work be approved?
• Will the engineer check the system against the insurer's requirements and the police response conditions?
• How are keyholder, site access and contact details updated?
• What happens if the system is no longer supported or the signalling path needs an upgrade?

Compare the scope of the maintenance contract, not just the number of visits. A cheap contract that excludes communication testing, batteries, reports or emergency support may leave the business with a false sense of protection.

FAQ: commercial intruder alarm servicing

How often should a commercial intruder alarm be serviced?

Plan for twice-yearly professional servicing if the alarm is monitored by an ARC. An audible-only alarm is generally checked annually. The insurer, manufacturer, alarm grade, police response policy and risk at the premises can require a shorter or different interval.

Is intruder alarm servicing a legal requirement for a business?

There is no single service interval that applies to every commercial intruder alarm under one UK law. Contractual, insurance, police response and system requirements can still make documented maintenance essential for the cover or response the business expects.

What is checked during an intruder alarm service?

The engineer should check the panel, user equipment, detectors, contacts, sounders, tamper circuits, batteries, signalling, event history, false alarms, site changes and response records. The exact tests depend on the system design and monitoring arrangement.

Can an existing intruder alarm be serviced by a new company?

Often yes, but the new maintainer should inspect the equipment, records, condition, signalling and available spares before accepting responsibility. A takeover inspection separates equipment that can be maintained from faults, unsupported parts or missing information.

What should I do if my intruder alarm keeps going off?

Keep the system protected, follow the ARC procedure and arrange a prompt fault investigation. Do not leave a detector bypassed without recording the risk and arranging a repair. Repeated false alarms can affect police response and usually point to a fault, environmental issue, user problem or design change.

Arrange a commercial intruder alarm service

FIDEC provides commercial intruder alarm installation, maintenance and fault support for businesses across Manchester, Greater Manchester and further afield. We can review an existing system, test its response chain and explain whether it needs routine maintenance, remedial work or a wider upgrade.

See the commercial intruder alarm maintenance service, read the business security alarm buyer's guide, or request a site survey. You can also call 0333 3662 007 or email info@fidecss.co.uk.