Cookies at Which? We use cookies to help improve our sites. If you continue, we'll assume that you're happy to accept our cookies. Find out more about cookies

Burglar alarms and home security

Burglar alarms

By Liz Ransome

Article 1 of 7

Put us to the test

Our Test Labs compare features and prices on a range of products. Try Which? to unlock our reviews. You'll instantly be able to compare our test scores, so you can make sure you don't get stuck with a Don't Buy.

Burglar alarms

Find out about the different types of burglar alarms, with advice on how to choose between them. 

You're less likely to become a victim of burglary if you have a well-fitted and maintained burglar alarm system, according to London's Metropolitan Police, and a Which? survey of ex-burglars.

The best type of alarm for your home depends on your personal preferences, your budget, where you live, what your home is like and what level of protection you need.

A key consideration is what you would prefer to happen when your alarm goes off. Bells-only alarms make a noise, but don't contact anyone (such as the police or the homeowner). A speech dialler system meanwhile, automatically contacts you or other nominated friends and family when the alarm is triggered. Alternatively, you could get a monitoring contract, whereby you would pay a company monthly or annually to take action or call the police if the alarm goes off. 

Costs vary between the different alarm types; you can visit our page on burglar alarm costs to find out more about pricing and getting the best deal, with insider tips from installers. 

Wireless or wired burglar alarm?

Alarms can be either wired or wireless. Wireless alarms look nicer, are generally easier to install and can be removed more easily if you move house. They use battery-powered sensors that communicate with a control panel using radio signals. 

While this type of alarm tends to be cheaper to install professionally, or can be fitted yourself, the alarms themselves can be more expensive. Wired systems usually need to be installed by a professional, as the wires will need to be hidden, so labour costs are higher.

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

Bells-only burglar alarm 

When a bells-only (also called 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. However, unlike a monitored alarm or one with a speech dialler, it won't automatically contact a named person or the police, so there is no guarantee that anything will be done. 

46% of Which? members who have a burglar alarm have a bells-only one. 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 giving you confidence that someone will call the police? Or perhaps you have friends and relatives who live very 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. 

Discover the top rated burglar alarm companies, according to our survey of more than 1,800 burglar alarm owners.

Maintaining your burglar alarm 

Regular maintenance should highlight and reduce defects, give you peace of mind and give you more redress if something goes wrong - 35% of Which? members with a burglar alarm 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 want a police-monitoring contract) either by an installer coming to your home, or remotely by the company contracted to do so. 

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, and gives you tips on how to get the best deal. 

Having your alarm system professionally maintained can help tackle any problems with false alarms. It is also a requirement of some insurance companies, and a requirement if you want a monitoring contract in addition (see below).

Burglar alarm monitoring 

There are three options if you would like to have your burglar alarm monitored, so someone will be alerted if it goes off: a speech dialler, a keyholder contract or a police contract.

You can get a monitoring contract for a wired or wireless alarm, but the alarm itself and the installation needs to conform to certain standards - see our page on choosing an installer for more details.

There are two types of monitoring contract: keyholder and police response. With both types, you pay extra per month or annually to have your alarm system monitored, which means the nominated keyholder or the police will be alerted when the alarm goes off - 17% of Which? members with an alarm have a monitoring contract.

The idea is that the alarm system connects to a receiving centre, so if your alarm is triggered, it will be notified. The receiving centre will first of all ring your home asking for your password identification. If this is incorrect or no one answers, either it will take action, inform the keyholder(s), or call the police, depending on what type of contract you have. 

Speech dialler 

A speech dialler (also called text alert), is a device built into or connected to a wired or wireless alarm. The idea is that when the alarm goes off, the speech dialler will call or text a set of phone numbers of your choice, for example family members or your mobile, until it gets an answer or can leave an automated message. 

This can be a good alternative to a professional monitoring service (see below), as a professional service involves monthly fees. Speech diallers are usually free as they are built into the alarm, so they just need to be activated or connected to the phone line. 

You can find out more about costs in our guide to burglar alarm and installation costs.

Keyholder monitoring

Keyholder monitoring is done through a company (the 'receiving centre'), which will either respond itself when the alarm is triggered, or will contact your nominated keyholders. These companies usually offer maintenance contracts, too, and can remotely check for problems - just make sure you get a breakdown of any extra costs this could incur before committing to buy.

Nominated keyholders must be 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 that monitoring contracts with nominated keyholders is any better than having a speech dialler, especially as there's an annual cost involved. However, the 24-hour service offered by monitoring, as well as knowing there is a dedicated company which is liable if action isn't taken, may offer you piece of mind.

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 monitoring

In addition to a receiving centre being made aware your alarm is going off, this type of contract means the police will also be contacted by the receiving centre. If you would like this kind of contract, it's important to check that the company is registered with the local police force. 

When your alarm goes off, two indicators within the house, such as a door contact and a sensor, must both have been triggered to warrant police call out. This is to avoid false alarms wasting police time. The Metropolitan Police say that a massive 92% of all alarm activations nationally in recent years have been false alarms.

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 won't guarantee 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 and what other resources are available. ‘If we’re fairly certain there’s someone in the premises, it’s a higher priority.’