The Crime Prevention Website


During research interviews by criminologists and post arrest interviews by me and many of my colleagues over the years most burglars (who expressed a preference) said that they were definitely put off by alarms!  Although I personally believe that a monitored alarm is an excellent deterrent in its own right everybody, including the police and your insurers, will expect you to also achieve a minimum level of physical security as well.  In fact everybody will tell you to sort out the physical security first and only afterwards put the alarm in.  So be very aware that if you do have a top of the charts, bells and whistle alarm system in place and you get burgled and it’s discovered that you don’t have the right lock on your front door, your insurers may refuse to pay your claim.

My audience from the USA might wish to view guidance available on Consumer 

Click DIRECTORY to see list of products relevant to this advice

Bradling Security

Bradling Security Ltd (BSL) is a supporter of this website and is an established independent security company with over 20 years of experience in the security industry. BSL is approved by the SSIAB for the installation, maintenance and monitoring of intruder alarm systems.

The company offers a personal service to their customers and in many cases a dedicated and experienced engineer will be assigned to look after specific client's needs. Their risk assessors and surveyors have a wide range of experience in the world of security and crime prevention including a former Metropolitan Police Crime Prevention expert.

BSL is based in Essex and provides security services in London, Hertfordshire, Essex and across the South East. They provide security services to small domestic homes to large businesses and local authority properties.

BSL provides: Crime Prevention Advice; Intruder/Burglar Alarms; CCTV; Access Control; Fire Alarms; Roof protection; Monitoring services and Maintenance

The basics

'Wired' and 'Wireless' alarms

There are two types of intruder or burglar alarm systems: 

Wired alarms comprise a number of electronic sensors that are connected to a control panel by low-voltage wiring and are governed by the BS EN 50131 and BS 4737 series of standards.  These are installed into new homes and into existing homes during refurbishment as it is more convenient to run the wiring at these times.

Wireless alarms as the word suggests, use battery powered sensors that are ‘connected’ to a control panel by narrowband RF signals (radio signals).  These used to be governed by BS 6799, but are now included in the BS EN 50131 series of standards for alarms.  These are quick to install and are used for homes where you don’t want to disturb the decor.  The only minor downside is that the sensor batteries have to be changed from time to time.

When a sensor (e.g. Passive Infra-red detector, door contact, microphone) the sensor will send a signal to the control panel. The control panel will then activate an internal and or external audible and visual alarm. 

If the alarm is the type that can send a signal to a remote alarm receiving centre (ARC) it will do so and the ARC will carry out your instructions to inform a range of people, such as a professional keyholding service, you, or another keyholder.  Once the ARC has received a confirmation signal from the alarm system the ARC will inform the police if that is what you have arranged for.

As far as the police are concerned there are also two types of alarms; Type A and Type B and there’s a big difference between them.  The table below identifies the differences.

Type A and Type B intruder alarms – the differences




Does the alarm system, its installation and maintenance have to meet a certain standard?


Yes, a type A alarm must be installed and maintained to the following standards: British Standard BS EN 50131 series or BS 4737 series (See Security standards Alarms for the series of documents)


Technically no, BUT if you’re using an alarm installer that is a member of  the National Security Inspectorate (NSI) or Security Systems and Alarm Inspection Board (SSAIB) then I strongly suggest that it is, in the event that you later require automatic attendance by the police

Who can install my alarm system?

The alarm has to be installed and maintained by a company that is a member of the National Security Inspectorate (NSI) or Security Systems and Alarm Inspection Board (SSAIB)

The police hold a list of recognised companies who are approved to install Type A alarms. However they do not provide this information to the public and will instead refer you to the inspection bodies above

If your installing company subsequently loses its police recognition their customers are given 3 months to make alternative arrangements

Anybody who is competent, including you, but I would recommend an alarm company that is a member of the National Security Inspectorate (NSI) or Security Systems and Alarm Inspection Board (SSAIB). 

Alarm companies that are members of these bodies may be advertising on this website.

The police do not recommend alarm companies to the public.

Who can monitor my alarm?

For police response your alarm must be monitored by an Alarm Receiving Centre (ARC) that is approved by the police.  The police normally require that the ARC  conforms to BS 5979: 2007 Category II , but certification to this standard is not always required under certain conditions

There are probably some Alarm Receiving Centres that will monitor your alarm, but they will only be able to contact you and your keyholders.

You have also arrange for text messages to be sent to your phone in the event of an activation

Police attendance

For Type A alarms there are two levels of response:

Level 1 – Immediate/urgent

The police do not guarantee to attend within a certain time period and attendance will be determined by the level of demand on police resources at the time and their other priorities

Level 3 – No response

(The ARC will instead only be able to inform your keyholders) – See below:

There has been a steady increase in the availability of DIY intruder alarms, personal attack alarms and CCTV systems, many of which have the ability to activate alarms and automatically send signals/messages to people’s landline and mobile telephones and computers.  As the majority will not meet European and British standards and will not be monitored by an approved Alarm Receiving Centre (ARC) the police will not attend the venue unless: 

There is some additional indication from a person at the scene that a criminal offence is in progress, which indicates that a police response is required.  Any additional electronic confirmation of the alarm activation (required by Type A systems) will not achieve police response.

The police do not guarantee a response to Type B systems and should your neighbours hear your alarm activate they should pass on the information using the police telephone number or 999 as appropriate.  The police will only attend if they are satisfied that a criminal offence is in progress.

Automatic dialling equipment must not be programmed to call police telephone numbers and calls received from unapproved ARCs or from ARCs without a valid Unique Reference Number (URN) will not receive a police response.

What happens if I have false alarms?

If your alarm system generates 3 false calls in a rolling 12 month period you will lose your Level 1 response

Following 2 false calls in 12 months you will receive a letter from the police advising you of the situation and recommending urgent remedial action

After withdrawal of police response your system will continue to be monitored by the ARC and a period of 3 months free of false alarms will enable your system to once again receive a Level 1 response.  If the rate of false alarms is such that reinstatement of police response has been delayed for more than 6 months your URN will be deleted and you’ll have to reapply for a new one

You will drive your neighbours mad and, after too many false alarms, your neighbours won’t even bother to look in the direction of your house when it goes off – having reached the ‘cry wolf’ situation.

If the false alarms keep on happening you could find yourself in trouble with the local authority and could experience the embarrassment of having a noise abatement notice served on you.

If the system is causing false alarms do investigate the problem thoroughly with your alarm installer and if it’s a system that you installed, perhaps you should go for a professional installation next time.

Do I need to supply Keyholders?

Yes, the ARC must hold the details of 2 keyholders or the details of a central keyholding service.  Keyholders must be able to attend your home within 20 minutes at any time of the day and night, have access to the relevant parts of the dwelling, be able to operate the alarm and be contactable by phone.

The police service does not hold keys.

Yes, because I recommend you register your alarm system with the local authority and so you will obviously need somebody to be able to attend your home when you are away.

Local authorities operate a voluntary registration scheme for intruder alarms and a registration will cost you a few pounds.  


Purchase from £400 +++ annual maintenance charge and monitoring fee if you want the police to attend (Type A)

Rental from £99 installation + a monthly monitoring charge of £20+ 

Registering your alarm with the local authority will cost around £10 - £15

The police issue a unique reference number (URN) for each Type A alarm.  In 2015 the charge to you for this is around £50

A monitored alarm requires two service visits by your alarm company per year

DIY Kit £120+++

Purchase from £300+++

Registering your alarm with the local authority will cost around £10 - £15


Choosing an alarm company

Being a fairly expensive purchase and one where you are likely to have a long term relationship with the alarm company I would suggest that you start by visiting the websites of the two organisations shown below.   Companies who are members of these bodies will be able to install an alarm to the standards required by the police for a police response, if that’s what you want.  Both sites enable you to carry out a search in your local area using your postcode. 

If you are tempted to buy an alarm from a company that calls at your door I would strongly advise you not to make a decision to buy at the time.  See my further advice about the 'dark side' of the alarm industry below. 

National Security Inspectorate (NSI)

Sentinel House
5 Reform Road

Tel:                         01628 637512

Security Systems and Alarm Inspection Board (SSAIB)

The Smoke Houses 
Cliffords Fort 
North Shields 
Tyne & Wear 
NE30 1JE

Tel:                         0191 296 3242
Fax:                        0191 296 2667

I suggest you get three quotes

If you choose a company that is a member of either the NSI or the SSAIB you should expect the following:

  • A thorough, written risk assessment survey of your home
  • A good standard of workmanship
  • Staff who have been security vetted to BS 7858:2006+A2:2009
  • A 24 hour call out service and able to respond within 4 hours
  • A company that is regularly inspected by the NSI or SSAIB to ensure compliance to standards and codes of practice
  • Insured to cover all eventualities in respect to installing and maintaining your alarm system
  • An alarm system that will meet the requirements of the police and your insurers and a ‘certificate of compliance’ to provide to your insurer if requested
  • An ISO 9001 Quality Management System
  • An offer to maintain your alarm system, which you will require if you want police response
  • The use of the latest and most reliable equipment to minimise the chance of false alarms

Once you have received the three quotes:

  • Compare the three companies’ equipment recommendations and the location of the various sensors
  • Compare the installation and ongoing maintenance costs
  • Establish if you will own or rent the alarm equipment
  • If you are having a monitored alarm find out how much the monthly monitoring fees will be 
  • Make sure that the installation will be to the British and European standards quoted above and that the audible alarm will switch off after no more than 20 minutes
  • Read the small print

On installation:

  • The installer will walk test the various sensors to make sure they are working
  • The installer will show you how to use the system and explain how it works
  • You should read the instructions you are given and ensure that any maintenance log is kept in an easy to find place – usually near to the power supply cabinet
  • Ensure that your family members and your TWO keyholders know how to operate the system

In addition:

  • Consider registering your alarm with the local authority
  • Inform your neighbours that you have an alarm 
  • If it doesn’t have police response let your most trusted neighbours know this and ask them to check the security of your home should the alarm activate and call the police if they suspect a criminal incident is in progress 

The Security Systems Policy of the Association of Chief Police Officers

The Association of Chief Police Officers (ACPO) of England, Wales and Northern Ireland has developed this policy to detail the response that can be expected to an alarm system (and other electronic security systems).  It identifies the requirements that such systems must comply with including recognised standards or codes of practice controlling manufacture, installation, maintenance and operation.  It also requires that the installation and services provided by the installing company and the Alarm Receiving Centre  shall be certified by a United Kingdom Accreditation Service(UKAS) accredited certification body.  Each police service may have additional requirements

A copy of the ACPO Security System Policy can be found here

Frequently asked questions

For more information about alarms please follow this link to Frequently asked questions

The Dark side of Alarms

Fortunately the majority of people working in the alarm industry are decent, law-abiding citizens and have your best interests at heart. Very occasionally a bad apple comes along, which often results from a cold call, either at the door or on the phone.  If you'd like to know more please follow this link to The Dark side of Alarms

Updated January 2015