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29 June 2021

How to buy the best burglar alarm

Find out about the different types of burglar alarm available, and read expert advice on how to decide which one is right for you.
Liz Ransome-Croker
Setting a burglar alarm 465031

According to both London's Metropolitan Police and a Which? survey of ex-burglars, you're less likely to become a victim of burglary if you have a well-fitted and well-maintained burglar alarm system. That means fitting one is a worthwhile investment.

The best alarm for your home depends on your personal preferences, your budget, where you live, what your home is like, and what level of protection and response you're after.

To help you make the right choice, watch the video above for a breakdown of what you need to consider when buying a new burglar alarm.

Video: how to buy the best burglar alarm

Types of burglar alarm systems

Firstly, you need to decide what you would like to happen when your alarm goes off:

  • Bells-only alarms make a noise, but don't contact anyone (such as the police or you). 
  • Dialler burglar alarms automatically dial your phone number, or that of nominated friends and family, when the alarm is triggered.
  • Smart home-security systems contact you or family members when the alarm goes off through a smartphone or tablet app.
  • A monitoring contract means you pay a company monthly or annually to take action or call the police if the alarm goes off. 

Scroll down for more information on each of these options. Costs vary between the different alarm types; visit our page on burglar alarm costs to find out more about pricing and getting the best deal, including insider tips from installers and our survey of burglar alarm owners. 

For ratings of big-name burglar alarm brands, such as ADT, Honeywell and Yale, based on the experiences of 2,083 alarm owners*, visit our guide to the best burglar alarm brands

Wireless burglar alarms

The second decision you'll need to make is whether to opt for a wireless alarm system or a traditional wired one. Wireless alarms use battery-powered sensors that communicate with a control panel using radio signals. 

These alarms tend to look nicer and are generally easier to install - you can often do it yourself. You can easily add additional sensors, and removing the system when you move house is a lot less tricky than for wired versions. 

However, wireless systems are usually more expensive, and you will need batteries for all components, such as the control panel and all sensors.

Wired systems, on the other hand, need wires running to each of the sensors to work - more than half of people we surveyed have a wired alarm (52%). These systems may be cheaper to buy, but they are more expensive to have installed: the wires need to be hidden away, so labour costs are higher. 

Find out more about the installation process, and the costs, by visiting our guide to choosing a burglar alarm installer.

If you're ready to get a burglar alarm installed you can use our Which? Trusted Trader service. All of our endorsed traders have been thoroughly vetted and checked by ex Trading Standards assessors so you can be ensured that whoever you hire is a reliable local trader. 

Use our search tool below to find a Which? Trusted Trader in your area.

Bells-only burglar alarm 

When a bells-only alarm (also called an audible alarm) is triggered, it makes a loud noise, which will hopefully alert someone in the area to the situation and/or scare off an intruder. 57% of the people we spoke to own one of these types of alarms. 

However, unlike a monitored, dialler or smart alarm, it won't automatically contact a named person or the police, so there is no guarantee that any action will be taken if you're out. 

It's worth thinking about the kind of area you live in before deciding to get a bells-only alarm. Is there an active neighbourhood watch that gives you confidence that someone will call the police in an emergency? If not, do you have friends and relatives who live close by who you could count on to take action?

You can install one of these alarms yourself, or you can pay a one-off fee to have it installed by a professional. 


  • You don't have to pay for a monitoring contract (read more on these below).
  • Having an alarm, no matter what type, can help to deter a burglar.
  • You can install it yourself.


  • You won't be alerted when your alarm goes off unless someone nearby hears it and knows how to contact you.
  • Without anyone to stop a break-in, the alarm on its own may not deter burglars.

We've spoken to former burglars to find out which security measures are more likely to prevent a burglary. Read do burglar alarms and CCTV work? to find out what they had to say. 

Dialler burglar alarm

If you're not comfortable with the idea of relying on a neighbour to let you know if your alarm goes off, you could consider a dialler alarm, also called an auto dialler. 

With these alarms, the dialler will contact you, or nominated friends and family, when your alarm is triggered. This means that you or they can then contact the police or ask a neighbour to investigate the issue.

Most dialler alarms allow you to programme a list of between three and 10 phone numbers, which will be called in the priority order you've set. The first person it successfully contacts is able to stop the rest of the numbers from being contacted.

Some more hi-tech models can also alert you if there is a fire or flood in your home, or connect to a panic button. 

There are two types of dialler alarm:

  • Speech diallers use your phone line to call the numbers you have assigned. This means you'll need to have a landline, and wires connecting it to the alarm.
  • GSM diallers use mobile network signals, so you don't need a phone line and there's no need to run wires. But you will have to buy a Sim card and make sure it's topped up with enough credit to make the calls when needed. You'll also need to make sure your home has a strong mobile phone signal before you go ahead.
  • You won't have to pay for a monitoring contract.
  • You or the people you've nominated will be alerted when the alarm is triggered.
  • If you buy one with additional detectors, it can also warn you about other dangers, such as fires.


  • You or your nominated contact(s) might be unavailable when alerted.
  • If you choose a GSM dialler, a weak mobile network signal will affect how well it works.
  • If you get a speech dialler, you'll need a landline and will have extra wiring in your home.

Smart home security

Smart home-security systems connect to your smartphone or tablet, or those of family members. This means you, or they, will be alerted when your alarm is triggered. These systems also allow you to control your smart security from your phone, even when you're away from home.

There are a lot of options when it comes to smart home security. In all cases, you will need a central hub that connects to all other compatible devices via wi-fi, in the same way that a standard alarm connects to sensors around your home. 

You can then connect elements to it, depending on the system you choose, including motion sensors, cameras, and lighting sockets that allow you to switch lights on and off when you're out.

You can install smart systems yourself, although a professional installer will know the best possible positions for the items you've chosen. 

Smart systems can be expensive, especially if you want to add a lot of extra components. A basic kit can cost around £200, but will come with only the main hub and a few sensors. It's likely you'll need more to cover your entire house.

We've tried out a number of smart home-security systems to see how easy they are to set up and use, and asked a security expert to assess how likely they are to deter an intruder.

Visit our guide to smart home automation to find out what other smart security gadgets are available, including door locks and security lights.


  • Sends alerts when you're away from home.
  • Can be monitored and controlled from your smartphone.
  • You can set up a smart system yourself.


  • Not all smart security systems are a deterrent - it depends on the components you get and where you place them.
  • As with a GSM dialler, whether or not you're alerted depends on your mobile network signal.
  • They can become expensive depending on the elements you choose.

Monitored alarm systems and contracts

If you want more peace of mind that a problem at your home will be dealt with quickly, you could consider a burglar alarm with a monitoring contract - 38% of the people we spoke pay for one of these.

You can get monitoring contracts for wired or wireless alarms, but both the alarm itself and the installation must conform to certain standards - you won't be able to install it yourself. 

There are two types of monitoring contract: keyholder and police response. In either case, you pay a monthly or annual fee, and then the monitoring company will alert a nominated keyholder or the police when the alarm goes off.

The alarm system connects to a receiving centre, which is notified each time your alarm is triggered. First, the receiving centre will call your home's landline to ask for password identification. If this is incorrect or no one answers, it will take action. This is either to inform the keyholder(s), or to call the police, depending on what type of contract you have.

Keyholder burglar alarm monitoring

Keyholder monitoring is done through a company (the 'receiving centre'), which will either respond itself when the alarm is triggered, or contact your nominated keyholders. Of the people we spoke to who have a monitoring contract, 75% have a keyholder one.

These companies usually also offer maintenance contracts and can remotely check for problems - just make sure you get a breakdown of any extra costs this could incur before committing.

Nominated keyholders must live within 20 minutes of the house, be able to drive, and have access to the house. It's your responsibility to keep the alarm company up to date with their details, and suggest alternatives if they are away. 

A number of installers we spoke to didn't believe monitoring contracts with nominated keyholders are any better than having a dialler, especially as there's an annual cost involved. However, the 24-hour service offered by monitoring may make you feel more secure, and the company will be liable if no action is taken in the event of a burglary.


  • Some companies also offer alarm maintenance.
  • A dedicated company is on hand to take action if there is a problem at your home, and is liable if it doesn't.


  • It costs money each month or year.
  • You cannot install the system yourself.
  • Keyholders must live close to your home, and it's up to you to keep your contact list up to date.

You can read more about what burglar alarm installers recommended to us, as well as how their advice varied, on our burglar alarm and installation page.

Police burglar alarm monitoring

This type of contract means the receiving centre will contact the police when your alarm is triggered - 52% of alarm owners that answered our survey have a police contract, which you can have in addition to keyholders. 

If you would like this kind of contract, it's important to check that the company you choose is registered with the local police force. 

When your alarm goes off, two indicators within the house, such as a door contact and a motion sensor, must both have been triggered to warrant police call-out. This is to avoid false alarms wasting police time. 

According to the Metropolitan Police, a massive 92% of all alarm activations in the UK in recent years have been false alarms. In our survey, we discovered that 43% have experienced a false alarm, and half have had more than one.

If your system has three false alarms (four in Scotland) in 12 months, you’re struck off the police register, and they won’t respond if the alarm goes off. 

It's worth noting that paying for this service doesn't guarantee that the police will come out. One police officer we spoke to, DCI Taylor, said that whether police go to your home - and how quickly - depends on what other incidents are happening at the time, and what resources are available. He said: ‘If we're fairly certain there's someone in the premises, it's a higher priority.’


  • The police will be automatically contacted if your alarm goes off.
  • Some companies also offer alarm maintenance.


  • You have to pay a monthly or annual fee.
  • You can't install the system yourself.
  • There is no guarantee that the police will go to your home.
  • After a certain number of false alarms, the police won't respond to any call-outs.

Maintaining your home alarm 

With any standard burglar alarm, regular maintenance should highlight and reduce defects, give you peace of mind, and give you more redress if something goes wrong - 79% of the alarm owners we surveyed have their alarm maintained.

If you get a burglar alarm maintenance contract, your alarm will be checked once a year (twice a year if you have a police-monitoring contract) either remotely or by an installer coming to your home. 

Costs for this vary, particularly as you can get different levels of maintenance, such as additional free call-outs or parts included. Our page on burglar alarm costs details what we found when we called a number of different installers for quotes, and shows you how you can potentially save nearly £400 on your alarm system and installation.

Having your alarm system professionally maintained can help tackle any problems with false alarms. It is also a requirement for some insurance companies, and if you have a monitoring contract.

*In January 2019, we surveyed 2,083 members of the public who own a burglar alarm about their system. Data has been weighted to be representative of the GB/UK population (aged 18+).