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House locks and home insurance, explained

How house locks affect your home insurance

The type of lock you use to secure your home has a direct effect on your home insurance premiums. Here’s everything you need to know about door locks and security

By Rachel Wait

Published: 08 November 2019

Unlocking front door

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You open and close your front door several times a day – but how much do you know about the lock you’re using?

Insurance firms consider all sorts of factors when working out how much your home insurance will cost, including anything from where you live to what building materials your house is made of. The way you lock your front door and ground-floor windows is an important consideration.

There are several different types of locks commonly used to secure doors and windows, and which one you use can have a significant effect on your home insurance premiums.

Don’t let the terminology confuse you, either. Because locksmithing is a very old profession, the words for most locks can be confusing – but don’t worry, we’ll explain everything you need to know.


How your door lock affects your home insurance

According to MoneySuperMarket data correct as of September 2019

Five-lever mortice deadlock

This is one of the most common types of lock, and it’s usually installed on wooden front doors. It involves a cavity cut into the door – which is called a ‘mortice’ – where the actual lock is fitted.

The levers are what the key has to move in order to ‘throw’ the ‘deadlock’ – ie to move the block of metal that prevents the door from opening. So the more levers a mortice lock has, the more secure it is – because you need more points of contact to pick it. You can buy three-lever mortice locks, but British Standard BS3621 states that five is the minimum level of security.

Insurers tend to insist that every exit door and ground-floor window is secured with a five-lever mortice lock conforming to BS3621 before they offer cover.

Most insurers will knock up to 5% off your home contents insurance premiums if you a lock which features the Kitemark on it, as this guarantees it has been manufactured to a certain standard.

Of course, you must actually be using the locks if you want to make a successful claim; insurers are likely to refuse to pay if burglars break in through a window that has been left open, regardless of whether you have the correct lock in place.

Multi-point locking system

A multi-point locking system is considered more secure than a mortice lock. This system has a minimum of three locking points – and often four or five – which all lock simultaneously when you turn the key, but it can’t be installed on every door.

These are the types of lock where you need to lift the handle up to lock properly, and some people can find the extra steps confusing, but they are considered more secure.

Multi-point locks are most common on uPVC doors. If they are on the main entrance to your home, you will need a lock cylinder with at least five pins for insurance purposes.

The Master Locksmiths Association recommends the use of locks with cylinders that are SS312 Diamond Approved, or which conform to the newer TS007 three-star Kitemark standard, both of which should protect against picking, drilling, bumping or snapping – the common methods which burglars use to disable locks and break in.

Nightlatches and rim locks

This type of lock is mounted onto a door rather than morticed within it. A nightlatch is much less secure on its own than a mortice lock, but if you install one as an additional security measure, it can cut your home insurance by a decent amount.

Double-locking nightlatches are the most secure variety, as they have a keyhole on the handle inside the door so that the latch can be deadlocked from inside. Look out for a nightlatch built to BS3621 standards, as this has been certified to a suitable level of security.

Key-operated window locks

You should ideally fit key-operated locks to all your downstairs windows. These are either fitted to the top or bottom of a window, or on the handle that closes the window.

So providing you remember to lock up when you leave the house, locked windows should knock a few quid off your premiums.


Common types of door lock

According to MoneySuperMarket data correct as of September 2019


Good security saves you money

Although installing locks can be expensive, you should be able to recoup the costs over the long-term with the lower insurance premiums a decent lock will bring. Effective security is a major deterrent to burglars, and your home will be safer for doing it. When taking out home insurance, always check each insurer’s required minimum security standards – failing to sort the right locks could invalidate your cover – and you may see a claim refused if you do fall victim to burglars. Comparing home insurance quotes with MoneySuperMarket is easy. You simply give us a few details – including information on how you lock your doors – and we will return a range of options from our partners for you to pick from.


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