A monitored intruder alarm is connected to a remote monitoring centre so that an alarm activation can be received and acted upon even when nobody is at the property. Depending on how the system and monitoring service are configured, the response may involve contacting nominated keyholders, a professional keyholding service or, where the necessary requirements are met, the police.
This is different from a standard audible alarm that simply sounds a siren at the premises. For businesses, landlords and other organisations where an empty building still needs protection, monitoring can provide an additional layer of security beyond the alarm bell itself.
In this guide, we explain:
- What a monitored intruder alarm is
- How an Alarm Receiving Centre works
- What happens when the alarm activates
- The difference between monitored and bells-only alarms
- How alarm signals reach the monitoring centre
- When keyholders or the police may be contacted
- What alarm confirmation means
- Why false alarms matter
- Whether monitored alarms need maintenance
- How to decide whether monitoring is appropriate for your premises
What is a monitored intruder alarm?
A monitored intruder alarm is an alarm system capable of sending signals away from the protected premises to a remote monitoring facility.
Instead of relying entirely on somebody nearby hearing an external sounder, an activation can be received remotely and handled according to an agreed response plan.
This can be particularly useful for commercial buildings that are empty overnight, warehouses, offices, retail premises, community buildings and other sites where nobody may be present when an alarm activates.
The exact response depends on the system, monitoring arrangement and level of protection required.
What is an Alarm Receiving Centre?
An Alarm Receiving Centre, usually shortened to ARC, is a facility that remotely receives and handles signals from connected security systems.
An ARC can operate continuously so that alarm signals can still be received outside normal working hours.
Depending on the arrangement, operators may receive information about an intruder alarm activation, signalling fault or other event and then follow predetermined procedures.
Those procedures could involve contacting a nominated keyholder, contacting a contracted keyholding service or, for qualifying systems and confirmed alarm conditions, passing the activation to the police.
The ARC is therefore separate from the alarm equipment installed inside the building.
What happens when a monitored alarm goes off?
The exact sequence depends on how the system has been designed and configured.
When a detector or another part of the alarm system identifies an event, the alarm control equipment processes that activation.
A signal can then be transmitted to the monitoring centre.
The ARC receives information from the system and follows the response procedure associated with that premises.
This could include:
- assessing the alarm information received
- checking whether the activation meets the required confirmation criteria
- contacting nominated keyholders
- contacting a professional keyholding service
- passing a qualifying confirmed activation to the police where the system has the appropriate arrangements in place
A monitored alarm should not therefore be thought of as simply a siren that also sends somebody a notification.
What is the difference between a monitored alarm and a bells-only alarm?
A bells-only alarm primarily relies on audible and visual warning devices at the premises.
If it activates, an external sounder may alert neighbours, employees, security staff or anybody else nearby.
However, if the building is isolated or nobody responds to the sounder, there may be nobody actively dealing with the activation.
A remotely monitored system can transmit the alarm to a monitoring centre instead.
That does not mean every monitored alarm automatically results in police attendance. The response depends on the monitoring agreement, system configuration, alarm confirmation and applicable police requirements.
Does a monitored alarm still have an external siren?
It can.
Remote monitoring does not necessarily replace the external sounder or internal alarm devices.
The audible alarm can still act as a deterrent and alert people at or near the premises, while the signalling system provides the remote connection.
The appropriate combination should be determined during the security system design.
A small office in Horley may need a very different arrangement from a large warehouse or multi-building commercial site elsewhere in Surrey or West Sussex.
How does the alarm send a signal to the monitoring centre?
A monitored system needs an alarm transmission path between the premises and the monitoring centre.
Modern signalling arrangements can use different communications technologies, and some systems use more than one communication path to improve resilience.
This is important because an intruder alarm should not become ineffective simply because one communication service fails.
The appropriate signalling arrangement depends on the risk, system specification and response requirements.
JPEC Fire & Security can consider the signalling requirements when designing or upgrading the alarm rather than treating monitoring as an afterthought.
What is dual-path alarm signalling?
Dual-path signalling uses more than one route for communicating alarm information.
The principle is that if the primary signalling route becomes unavailable, another route can provide additional resilience.
This may be particularly relevant where a business needs a higher level of security or where the alarm forms part of an insurer or police-response requirement.
The specific technology used should be selected according to the required performance rather than simply assuming every monitored alarm needs exactly the same communications equipment.
Will a monitored alarm automatically call the police?
No.
This is one of the most important distinctions to understand.
Having an alarm connected to a monitoring centre does not automatically mean every activation is passed directly to the police.
Police response to security systems operates under specific requirements. For a qualifying remotely monitored intruder alarm, this includes requirements around the installer, monitoring centre, system standards, maintenance and alarm confirmation.
Where those arrangements are not in place, the monitoring service may instead notify keyholders or another nominated response service.
The required response should therefore be agreed when the system is specified.
What is a police URN for an alarm?
A URN is a Unique Reference Number associated with a qualifying security system registered for police response.
It identifies the protected premises and alarm system within the police response arrangements.
A URN is not simply obtained by buying an alarm with a particular feature.
Systems intended for police response need to meet the applicable requirements, including the use of recognised installers and monitoring arrangements.
If police response is required for a particular property, this should be established during the design stage rather than after the alarm has already been installed.
What does a confirmed alarm mean?
Alarm confirmation helps establish that an activation is more likely to represent a genuine security event rather than a single accidental trigger.
Depending on the system, confirmation can be achieved using approved methods and system design arrangements.
This is particularly important where an alarm is intended to generate a police response.
BS 8243 provides guidance for the design, installation and configuration of intruder and hold-up alarm systems designed to generate confirmed alarm conditions.
The technical confirmation method should be determined by the installer based on the system requirements and applicable standards.
Why are false alarms important with monitored systems?
False alarms create disruption for the customer, monitoring centre, keyholders and potentially the emergency services.
They can be caused by a range of issues including unsuitable detector positioning, user error, equipment faults, environmental conditions or changes to the premises.
For systems with police response, repeated false alarm calls can also affect the level of police response available.
This is one reason monitored systems need to be properly designed, commissioned, maintained and used correctly.
If a system repeatedly activates without an obvious cause, continually resetting it is not a substitute for investigating the fault.
Who gets contacted when a monitored alarm activates?
This depends on the agreed response plan.
Possible responses can include contacting:
- the business owner
- a nominated employee
- a landlord or property manager
- a nominated keyholder
- a professional keyholding company
- the police where the system and activation qualify for police response
The correct contact details need to be maintained.
If employees leave the business or responsibilities change, the monitoring information should be updated rather than leaving an old keyholder as the emergency contact.
What is a keyholder?
A keyholder is a nominated person who can respond to an alarm activation and access the premises where necessary.
For a business, this could be an owner, manager or another authorised individual.
Some organisations use professional keyholding services instead, particularly where it would be inappropriate for employees to attend an alarm activation during the night.
The decision should take account of staff safety as well as building security.
Employees should not be expected to put themselves at risk by confronting a suspected intruder.
Can a monitored alarm send alerts to my phone as well?
Many modern security systems can provide app-based functions alongside professional monitoring.
Depending on the system, an authorised user may be able to receive notifications, check the status of the alarm or perform permitted remote functions.
However, a smartphone notification is not the same thing as professional alarm monitoring.
A phone alert still relies on the recipient having their phone available, noticing the notification and being able to respond.
A professionally monitored arrangement provides a different type of response through the monitoring centre.
What happens if the internet goes down?
This depends on the alarm transmission system.
A properly designed monitored system should consider what happens if a communications route becomes unavailable.
This is one reason resilient signalling and, where appropriate, multiple communication paths can be important.
Businesses should not assume that because an alarm has an app it automatically has a resilient connection to a professional monitoring centre.
The signalling specification should be understood as part of the overall security design.
What happens during a power cut?
Intruder alarm systems normally incorporate standby power so that they can continue operating for a period if the mains electricity supply fails.
The required standby arrangements depend on the system specification.
Batteries do not last indefinitely and their condition forms an important part of alarm maintenance.
A system that has been neglected for years may have significantly reduced standby capability even though it appears to work normally while mains power is available.
Does a monitored intruder alarm need servicing?
Yes.
A monitored alarm should be maintained in accordance with the applicable requirements and the system’s specification.
Maintenance can include checking detectors, alarm devices, signalling, standby batteries and other system components.
NSI guidance states that systems signalling to an approved Alarm Receiving Centre require more frequent professional maintenance than a basic audible-only system.
Maintenance is particularly important where continued monitoring or police response depends on the system remaining compliant and reliable.
Can an existing intruder alarm be upgraded to monitoring?
Sometimes, but it depends on the existing equipment and its condition.
An engineer would need to assess the control panel, detectors, signalling capability, age of the equipment, existing installation and the response required.
In some cases, adding suitable signalling equipment may be practical.
In others, particularly where an older alarm no longer meets the required specification, replacing or substantially upgrading the system may make more sense.
A survey should establish this before monitoring arrangements are agreed.
Do insurance companies require monitored alarms?
Some insurers may specify particular alarm requirements depending on the property, contents and level of risk.
Those requirements can include the grade or type of alarm, who installs and maintains it, and whether remote monitoring is required.
There is no sensible one-size-fits-all answer because insurance conditions vary between policies.
If an insurer has specified security requirements, these should be provided to the alarm installer before the system is designed or changed.
Businesses should confirm the exact requirements directly with their insurer or broker.
Are monitored alarms only for large businesses?
No.
Monitoring can be relevant to businesses of different sizes where the consequences of an undetected break-in justify an active response arrangement.
A small retailer in Reigate, an office in Redhill or a workshop near Crawley may all have reasons to consider monitoring.
The decision should be based on the individual risk rather than the physical size of the organisation.
Factors such as location, opening hours, stock, equipment, previous incidents, insurer requirements and how quickly somebody could otherwise respond can all be relevant.
Are monitored alarms suitable for warehouses and industrial premises?
They can be particularly useful for premises that are routinely unoccupied for long periods.
Warehouses, workshops and industrial units may contain valuable stock, tools, vehicles or equipment while having nobody present overnight.
These sites can also have multiple entrances, loading doors and larger internal areas that require careful detector design.
A professional security survey can establish how the building should be divided into protected areas and what type of detection and signalling is appropriate.
Can CCTV work alongside a monitored intruder alarm?
Yes. CCTV and intruder detection can complement each other when they are designed around the same security objectives.
Intruder detection can identify an alarm condition while CCTV can provide visual coverage of relevant areas.
For some higher-level security applications, remotely monitored detector-activated CCTV can also form part of the response arrangement.
This needs proper system design and should not be confused with simply receiving a camera notification on a mobile phone.
JPEC Fire & Security can consider CCTV, intruder alarms and access control together where an integrated approach is appropriate.
What should a business consider before choosing monitoring?
Start with what you actually want to happen following an alarm activation.
Questions worth considering include:
- Who should be notified?
- Is keyholder response sufficient?
- Is police response required?
- Does your insurer specify an alarm standard?
- How long is the building normally empty?
- What assets are being protected?
- How reliable does the signalling need to be?
- Is there an existing alarm that could potentially be upgraded?
These questions help determine the required system before equipment is selected.
Should I choose the alarm equipment before deciding on monitoring?
Ideally, no.
The required response should influence the alarm design from the beginning.
Installing a basic system first and deciding later that police response or a particular insurer-approved monitoring arrangement is required can create unnecessary upgrade work.
A security survey should consider the premises, risk, required response and any insurer requirements before the final equipment and signalling specification is agreed.
JPEC Fire & Security can help
JPEC Fire & Security can survey, design, install, commission, service and maintain intruder alarm systems for commercial properties, landlords and organisations across Horley, Reigate, Redhill, Crawley, Surrey, West Sussex and surrounding areas.
We can assess the building, how it is used, when it is occupied and what needs protecting before recommending an appropriate alarm arrangement.
Where remote monitoring is required, the signalling and response requirements can be considered as part of the overall system design rather than added as an afterthought.
We can also assess existing intruder alarm systems where a business is considering an upgrade, and coordinate security requirements such as CCTV and access control where appropriate.
To arrange a security survey or discuss an intruder alarm system, contact JPEC Fire & Security.
This article provides general information and is not a substitute for a site-specific security assessment, insurer advice or confirmation of current police-response requirements. The appropriate alarm design, signalling, monitoring and response arrangements depend on the individual premises and level of risk.
