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. But there are various types of door lock available, so which one should you go for? If you can’t tell a deadlock from a dead latch, we’re here to help.

A woman puts a key in her front door lock

When you get a quote home insurance, insurers need to know what types of door locks you have on any outside or patio doors.

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

On the contrary, if your home has the best types of door locks, you could get a discount off your insurance price.


What are the different types of door locks?

It can be difficult to know what type of door 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 4 main types of door locks. These are:

  • 5 lever mortice deadlock
  • 5 lever mortice deadlock conforming to BS3621
  • Key operated multi point locking system
  • Rim automatic dead latch

The 4 types of lock types: 5 lever mortice deadlock, 5 lever mortice deadlock conforming to BS3621, key operated multi point locking system and rim automatic dead latch

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


What is a 5 lever mortice deadlock?

This is a standard deadlock, which offers moderate protection to the main doors into your home. You can lock it 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. The 5 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 5 lever mortice deadlock?

You’re likely to have a 5 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 5 lever mortice deadlock?


  • A step up from a 3 lever deadlock
  • It can be keyed alike - this means you can have 1 key for multiple locks


  • The door lock has been tested by the manufacturer only and doesn't meet British Standards
  • Might not stand up to the techniques used by burglars

What is a 5 lever mortice deadlock conforming to BS 3621?

This door lock type is the same as a 5 lever mortice deadlock.

The main difference is that the lock adheres to British Standard (BS) 3621. This means it 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 insist you have this type of lock to get cover.

Some insurers might lower your policy costs if you have this door lock type, so it's worth considering.

How do I know if I have a 5 lever mortice deadlock conforming to BS3621?

A BS3621 door lock has a Kitemark on the lock’s faceplate.

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

What are the advantages and disadvantages of a 5 lever mortice deadline conforming to BS3621?


  • Meets British Standards
  • Tested against lock picking and drilling


  • Only 1 locking point

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

A key-operated multi-point locking system bolts the door into the frame and locks at multiple points at the turn of a key. This type of door lock offers you a high level of security.

The door lock is common in more modern houses as you usually find it on patio doors made of UPVC.

As with the 5 lever mortice deadlock, these types of door locks need the key to lock and unlock the door. But the difference is 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 including:

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

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 need for your house
  • Only needs one cylinder, which can you can easily change or upgrade


  • The door handle must be lifted to double lock the mechanism
  • If you're unfamiliar with the locking method, you might not lock it properly

What is a rim automatic dead latch with key-locking handle?

If you have a rim automatic dead latch, 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 dead latches on their own – they’re usually paired with a mortice deadlock as an additional level of security.

The most common form of the dead latch 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 need the key. You often see these in flats and student accommodation.

How do I know if I have a rim automatic dead latch?

Dead latches and night latches should be easy to find if:

  • Your door is made of wood – dead latches don’t work on UPVC or composite doors
  • There’s another lock on the door as well - for example, a 5 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 dead latch?


  • 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?

It's up to you to decide. But demand for electronic and smart door locks are on the rise as our homes get smarter and more connected.

You might consider an electronic door lock that doesn’t need a key at all. Or, door locks that require you to enter a digital combination before unlocking.

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


How secure are smart door locks?

Many smart locks are Wi-Fi or Bluetooth. The major risk with these types of door locks is that they can be hacked.

Smart locks also need batteries to function. So if the battery ever runs out, your door might not be locked securely.

As smart locks are part of a new technology, they're usually seen as a higher insurance risk than a standard door lock. This could result in your your home insurance costs being higher.


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 5 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.


Will having a good door lock make my home insurance cheaper?

Yes, although it has a positive impact (as it lowers the risk of burglary), it's one of a range of factors that are likely to have more of an impact including:

Compare home insurance quotes


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 get cheaper home insurance – 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
  • Installing a security system

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