Types of door locks

If you’re looking to save money on your home insurance, it's important to get the right type of door lock fitted. If you can’t tell a deadlock from a deadlatch we’re here to help.

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A woman puts a key in her front door lock 

When you apply for a home insurance policy, insurers need to know what locks you have on any outside doors or patio doors

In some cases, if you don’t have the right type of locks, you might struggle to get cover at a reasonable price. This is because the insurer might not think your home is secure enough.

It’s always a good idea to compare home insurance quotes from a number of insurance providers to find a good deal. You might even get a discount off the normal premium if your property has the best types of door locks.


What are the different types of door locks?

When you compare home insurance quotes with us, we’ll ask you what type of locks you have on all of your outside doors.

This helps insurance companies work out how secure your property is. This in turn works out the risk of a break-in, which could impact your insurance costs.

It can be difficult to know which type of locks you have at home, but it's important to get it right. Otherwise, you could be at risk of invalidating your home insurance policy.

You can select one of four main types of door locks. These are: 

If you don't have one of these, choose ‘other lock type’ – and consider getting your security upgraded.

Compare home insurance quotes


What is a five-lever mortice deadlock?

This is a standard deadlock, which offers moderate protection to the main doors into your home. It's lockable from either side and is sometimes used with a night latch for added security.

You most commonly see these door lock types on timber doors. Five-lever mortice deadlocks use a key to lock and unlock, so there’s less risk of accidentally locking yourself out of your home.


How do I know if I have a five lever mortice deadlock?

You’re likely to have a five lever mortice deadlock if:

  • Your door is made of wood
  • The door doesn’t lock automatically when you close it
  • You can see the words ‘5 lever’ engraved on the faceplate of the lock


What are the advantages and disadvantages of a five lever mortice deadlock?


  • A step up from a three-lever deadlock
  • It can be keyed alike - this means you can have one key for multiple locks


  • The lock might have been tested by the manufacturer only and not meet British Standards
  • Might not stand up to the techniques used by burglars



What is a five-lever mortice deadlock conforming to BS 3621?

This kind of lock is the same as a five-lever mortice deadlock. The main difference is that the lock adheres to British Standard (BS) 3621.

This means that the lock meets the standards of the British Standards Institute as being secure against picking and drilling the lock.

This is the door lock of choice for many insurers. Some insurance companies might insist you have this type of lock to get cover.

Others might shave some money off your policy if you have it. Either way, it’s worth considering if you don’t have it.


How do I know if I have a five-lever mortice deadlock conforming to BS 3621?

The dead giveaway for a BS3621 door lock is that it’ll have a Kitemark on the lock’s faceplate.

There should also be a serial number that starts in BS3621.

These locks should also meet the criteria of standard five-lever mortice deadlocks as described above.


What are the advantages and disadvantages of a five-lever mortice deadline conforming to BS 3621?


  • Meets British Standards
  • Tested against lock picking and drilling


  • Only one locking point



What is a key-operated multi-point locking system?

A multi-point locking system bolts the door into the frame and locks at multiple points at the turn of a key, offering you a high level of security.

It's common in more modern houses as you'll usually find this type of lock on UPVC and composite doors. You often see these as patio door locks since the doors tend to be made of UPVC.

As with the five-lever mortice deadlock, these door locks need the key to lock and unlock the door.

One of the main differences is that a multi-point locking system locks the door at the top and bottom as well as the centre. This gives added strength to the weaker points of the door.


How do I know if I have a multi-point locking system?

There are a few key features that’ll tell you if you have a multi-point locking system:

  • The door is UPVC or composite
  • The door locks at multiple points along its height
  • You turn the handle up in order to lock it.


What are the advantages and disadvantages of a key operated multi-point locking system?


  • Multiple locking points 
  • Can be keyed alike, reducing the number of keys you’ll need for your house
  • Only needs one cylinder, which can easily be changed or upgraded


  • The door handle must be lifted and double lock the mechanism
  • Users who are unfamiliar with the locking method might not lock it properly



What is a rim automatic deadlatch with key-locking handle?

If you have a rim automatic deadlatch, it should be mounted on the inside of the door.

The cylinder inside the lock is linked to the keyhole on the outside of the door, allowing you to lock your door more securely from the inside.

You don’t often see deadlatches on their own – they’re usually paired with a mortice deadlock as an additional level of security.

The most common form of the deadlatch is the night latch. With these, the door locks as soon as it’s closed. If you’re inside, you turn the latch to open the door. If you’re outside, you’ll need the key. You often see these in flats and student accommodation.

The downside to these locks is that it’s much easier to lock yourself out of your home if you don’t have the key.


How do I know if I have a rim automatic deadlatch?

Deadlatches and night latches should be easy to spot:

  • If your door is made of wood – deadlatches don’t work on UPVC or composite doors
  • There’s another lock on the door as well e.g. a five-lever mortice deadlock
  • The lock is set into the surface of the door itself, rather than on the edge


What are the advantages and disadvantages of a rim automatic deadlatch?


  • Easy to operate
  • Door locks automatically on closing


  • Might require additional lock such as a 5 lever mortice to improve security
  • Easier to lock yourself out by accident



Are electronic door locks worth it?

Alternatively, you could consider an electronic door lock that doesn’t require a key at all. 

Demand for electronic and smart door locks are on the rise as our homes get smarter and more connected.

You can get door locks that require you to enter a digital combination before unlocking (to give your home that escape room vibe).

You can also get electronic door locks that unlock using your smartphone, as well as trusted devices for family members and friends.

But the major risk with electronic door locks is that they can be hacked. You can’t hack a deadlock.

As it’s such a new technology, your insurance company might rate it as more of a risk than a standard door lock. It may be worth talking to your insurance company if it’s something you’re considering.


What’s the best lock type for a front door?

We’re going to go with the insurers on this one. The safest kind of lock to get is likely to be a five-lever mortice deadlock that adheres to BS 3621.

Deadlocks tend to be harder to break into than other lock types, which is why many insurance companies recommend them.


What else can I do to keep my home safe?

Having a robust door lock is just one way you can keep your home secure. If you’re really keen to beat the burglars – and shave a few quid off your home insurance policy – you can try:

Keeping your valuables out of sight – that includes empty TV boxes you throw in the bin!

Securing important and hard-to-replace items

Being careful of who you tell when you’re going on holiday

Being careful who you give your keys to as it could invalidate your policy.

For more tips, check out your guide to how you can protect yourself from burglars.