House locks and home insurance

One of the most common types of lock, five-lever mortice deadlocks are fitted within a cavity in the door, which is called a mortice.   

The levers are what the key must move in order to ‘throw’ the ‘deadlock’ – i.e. to move the block of metal that prevents the door from opening. The more levers a mortice lock has, the more secure it is.

You can buy three-lever mortice locks, but most insurers want you to have at least five levers. This is what’s needed for the locks to meet the British Standards Institute (BSI) BS3621 lock standard. 

You may need BS3621 standard five-lever mortice deadlocks on all your external doors to get home insurance. Most companies will provide contents cover for a bit less if you have BS3621 locks on all your doors and ground-floor windows.  

A multi-point locking system has three, four or five locking points, all of which lock simultaneously when you turn the key. It’s a very secure system that strengthens the top and bottom of the door as well as the middle, but it’s only usually used on uPVC and composite – rather than wooden – doors. 

For insurance purposes, you will generally need at least five locking points to secure the main entrance to your home.

The Master Locksmiths Association also recommends the use of multi-point locking systems with cylinders that are SS312 Diamond Approved or conform to the newer TS007 three-star Kitemark standard, both of which should protect against attempted burglaries. 

Night latches, or Yale Locks, lock the door automatically when it closes and are often used alongside mortice deadlocks. From the inside, they can be opened by turning the latch; from the outside, they can only be opened using the key.  

Insurers don’t generally view locks of this kind as secure enough on their own, but as an extra lock they can earn you a discount on your home insurance. (As long as they meet the BS3621 standard.)

Euro cylinder locks are often used in conjunction with multi-point locking systems on uPVC doors, and they work by using a pin and tumbler system. Euro cylinder locks can be replaced without having to replace the multi-point locking mechanism, so they’re relatively inexpensive and easy to replace. 

They can be vulnerable to ‘lock snapping’, however, you can install an anti-snap lock to prevent this. Look for locks that have a TS008 3-star rating. 

Rim cylinder locks have a pin and tumbler design and are often used alongside nightlatches as the external operating point. Rim cylinder locks are replaceable without having to also replace the nightlatch. 

You can upgrade rim cylinder locks to conform to BSI lock standards. It’s likely insurers will request this in order to qualify for cover, as without this extra security these locks can be picked relatively easily. As such they should also always be used in conjunction with a nightlatch or mortice lock. 

Padlocks come in multiple shapes, sizes, and levels of security designed for different functions, and they’re a useful extra layer of protection for items in and outdoors.

Many people use padlocks to secure shed or gate doors, but keep in mind cheaper models can be broken easily with tools like saws or bolt cutters.

Upper-end models are often close-shackled, making them harder to break open, and some even come with fingerprint security. 

A key-operated security bolt can again be a useful extra layer of security for shed doors or gates, are easily fitted and operated and also fairly affordable.

However, they aren’t extremely secure so insurers may require you to place a bolt lock on both the top and bottom of doors they’re used on.  

Smart locks can be controlled via a key tag, keypad or mobile phone, using wireless technology to lock and unlock rather than a physical key.

Some come with extra functions, such as allowing you to monitor when someone leaves or enters through the door, or creating virtual keys for visitors.

For insurance purposes, you'll want to make sure it’s approved to meet the BS3621 standards and has the BSI Kitemark. 

Window latches are standard for double and single hung windows, connecting each window sash and preventing movement. These should only be used alongside other window locks.

Also known as casement locks, these are turned down to lock the window and turned up to release them. Casement windows come with folding locks as standard. 

Window pin locks work in a similar way to chain locks, with a cable attached to part of the lock on the sash and another part on the frame - they stop the window from opening further than desired. 

Window wedges limit how far a window can be opened, and can be adjusted as required from the inside.  

Key-operated locks are often used in conjunction with latch locks, requiring a key to open and close the window - insurers will generally prefer these, but check if your insurer lists window locks as a requirement.

Sliding window locks are also like chain locks but specifically for sliding windows, and will stop the window from opening further than wanted.

You have no way of knowing who has access to the existing lock and how many copied keys there may be.

Even if they return their key and you completely trust them, you won’t know if someone has made a copy of the key.

A burglar may use the same weakness in the lock as the last time they broke in. It's also possible that they may have stolen a key to copy. 

You don’t want to risk it being found by someone who has bad intentions and figures out where you live, so it’s best to replace your locks if you lose a key.

Broken or damaged locks are vulnerable and should be replaced as soon as possible. You may not be covered by your home insurance if you keep a faulty lock.

General rule of thumb is that you should replace your locks every seven years to combat wear and tear.