Keytek's Lock Guide

Door lock guide: Different types of door locks explained

With so many different door lock types on the market, it is hard to choose which door lock type will be best for you. Whether you are looking for a front door lock type, a back door lock type or even a bathroom door lock type, it’s best to make sure you are getting a lock that is effective. We have put together an easy guide to which type of lock is which, along with features and uses.

For key terms, go to our Locksmith Jargon Buster 

Mortice mechanism

What is a Mortice Lock?

Mortice locks are very common and are usually attached to a wooden door with a key being required to operate it.  This type of lock often sits flush within the door and is constructed in a way where it allows for the mechanism to be easily taken apart to be serviced and maintained.

The lock is operated by entering a key into the lock, the key operates a lever that throws across a bolt into the keep that is fixed within the doorframe therefore securing the door

Mortice locks can be known as a Deadlock or Sashlock. They both have essentially the same operating system, with the distinguishable difference between them being the use of a handle that operates a latch within a sashlock. This means that you are able to close the door using the latch without having to deadbolt the door, whereas to close a door with a Deadlock installed you must deadbolt the lock.


Advantages of Mortice Locks

Security: As they are fitted to the door themselves, they can be harder to be forced open over their cylindrical counter parts.

Adaptability: With a wide range of sizes they can be easily fitted to most doors with ease, and the range of different finishes means that you can choose the right hardware to suit your home.

Affordability: Due to the design, they are easily replaced, fixed, fitted and maintained.

Insurance Compliant:  Using a British Standard Mortice lock will make you complaint with most insurance policies minimum requirements.


Disadvantages of Mortice Locks

  • There is no automatic locking option for Mortice Locks
  • Mortice Locks cannot be installed on doors with a thickness lower than 35mm


How do I know if my Mortice Lock is British Standard?

There are 2 ways to identify to check if you have British Standard locks:

  1. Identify the British Standard Kitemark engraved on the lock
  2. Identify the British Standard number BS3621 under the BSI Kitemark.

The 2 steps to identify British standard

Find out more about British Standard here


Deadlock Cases

A Deadlock case has a similar functionality to that of the mortice lock; however instead of a lever employing the bolt, the bolt is thrown by a cylinder instead. This type of lock can often be found on interior doors that need to be locked at all times.


Advantages of a Deadlock case

Ease: if you should find that you do need to change your lock for security reasons, you can do so without changing the Deadlock case. You can just change the cylinder making it quicker and more affordable.

Multi-functional: You can have a master key set to a deadlock case as well as separate keys, ensuring that you can customise the use of the lock to your individual needs.


Disadvantages of a Deadlock case

  • Not as secure
  • Cannot be installed on a door with a thickness less than 35mm
  • Can be difficult and complex to fit which can increase Locksmith prices




Nightlatch with rim cylinder and keys


Commonly referred to as ‘Yale Locks’ these locks are known as secondary locks and are often found accompanying a mortice lock. A nightlatch sits higher up on the door, around shoulder height, and has the ability to automatically lock the door when it is closed. The locking feature on this mechanism allows for the latch within the lock to be locked internally so that the external cylinder is rendered useless, offering a layer of protection.


Types of Night Latches

Standard Nightlatch

This is the most basic version of the nightlatch and offers minimal security. With this model you will still get the automatic locking and use of the internal snib feature that allows you to either lock or hold back the latch.  This type is often found on communal doors where automatic locking is needed but you cannot have anyone being locked in the building.


Deadlocking Nightlatch

This model allows you to turn the key externally one full rotation in the opposite direction to opening in order to lock the lack into position. Similar to the functionality of the internal snib, this ‘double deadlocking’ feature allows you to deadlock the door externally, rendering the internal functionality non-functioning.


Auto-deadlocking Nightlatch

The security of the nightlatch increases at this model as the nightlatch will automatically deadlock the latch when closed. One deadlocked a key must be used to unlock the nightlatch. This model also has the additional feature of an anti-thrust latch, meaning that when engaged this will stop the latch from being slipped open.


Double Locking Nightlatch

One of the most secure nightlatches that you can have, this version has the added feature of an internal key meaning that you can lock the internal handle for extra security. These nightlatches are approved by British Standard BS3621 and BS8621.


Advantages of a Nightlatch

Security: The internal mechanisms on all of the types of nightlatch allows for automatic locking, so whenever the door is closed it is also locked.

Deadlocking:  Using either a snib or a handle you can deadlock the latch within the nightlatch halting the functionality of the external keyway.


Disadvantages of a Nightlatch

  • Is often not secure enough to be the only lock on a door and is often accompanied by a mortice.
  • Automatic locking means you can easily lock yourself out if the door shuts behind you unexpectedly.


Rim Cylinder

A rim cylinder is a classic pin tumbler design which houses a series of different length pins that secure the lock in place and when the correct key is inserted it can align all of the pins allowing them to turn, this is what allows the lock to open. The rim cylinder is often used as the external operating system for the nightlatch.


Advantages of a Rim Cylinder

Security: Rim cylinders can be upgraded to British Standard models, adding more security and meeting insurance policy minimum standards.

Affordability:  As a rim cylinder and nightlatch work together, most assume that if one is changed the other one must be as well, however this is not the case. You can easily change a rim cylinder without affecting the nightlatch, saving time and money.

Variety: Rim cylinder come in different finishes to ensure that you can create a cohesive aesthetic with the rest of your hardware.


Disadvantages of a Rim Cylinder

Security: If not to British Standard, rim cylinders can be picked with some ease.

Security: Alone is not ample security and should always be used in partnership with a mortice.




Multipoint locking system

Multi-Point Locking Systems

Commonly found on uPVC doors, the multi-point locking system have a minimum of 3 locking points which all lock simultaneously when the mechanism is engaged. Working in conjunction with a cylinder lock, when the door is locked the handle is turned up to engage the system and therefore securing the door. You can get different versions of the multi-point locking system with either 3, 4 or 5 locking points, with the general idea that the more locking systems there are the safer the door.


Advantages of a Multi-point Locking System

Security: Connecting the door to the door frame in this way makes it more difficult to force the door open.

Ease: To engage the system only one cylinder is needed, which will allow all of the locking points to lock simultaneously.


Disadvantages of a Multi-point Locking System

Price: As it is integrated into the door, it can be complex and pricey to replace the mechanism should it break or need replacing.

Reliability: The system overall is quite safe, however all the locks need to engage to be able to lock the door, which requires that all points will work simultaneously.

Stiffness:  A new multi-point locking system can be stiff at first when trying to lift the handles to engage the locking points, making it potentially difficult for the elderly or less able to operate.




Cylinder locks with keys

Euro Cylinder Locks

Euro Cylinder locks are another common type of lock found on front doors, normally on a uPVC door in conjunction with a multi-point locking system. This cylinder uses a pin and tumbler system with a key to align the internal pin set.

Advantages of a Euro Cylinder

Ease: Although paired together, you can replace a euro cylinder without having to replace the adjoining multi-point locking system, making replacing the lock easier and less expensive.

Security: Some models of euro cylinder can be restricted so that only the owner can request new copies of a key be made.

Commercial use: These cylinders can be key aligned so that one key can work for multiple cylinders.

Adaptability: Euro cylinders can be adapted to have an internal thumb turn from the standard keyway on each side for easy internal operation.


Disadvantages of a Euro Cylinder

Euro Cylinders can be vulnerable to a technique called ‘lock snapping’ employed by burglars. Lock snapping is a method that an intruder can use to gain entry into your house very quickly. All it takes is physical force alongside some makeshift tools to break in. Applying the right amount of pressure to a Euro Cylinder lock will allow for the outside to be removed exposing the mechanism, which is then subject to tampering.


How can I stop cylinder snapping?

This method of entry can be stopped by installing an anti-snap lock. These locks hold a higher security and are tested to be more resistant to attack. An anti-snap lock will snap, but has been manufactured to snap in a certain place, this ensures that the central section that will grant access is still protected and as the cylinder has snapped it makes it more difficult for someone to force entry and a burglar will not be able to tamper with the mechanism.

We at Keytek® recommend the ABS High Security Euro Cylinder, which is the only security cylinder currently on the market which has a TS007 3 star rating, SS312 Sold Secure Diamond Accredited and Secured by Design Accreditation combined. We also recommend installing at least a 3 star security solution, you can do this by either installing a 3 star security cylinder (as mentioned) or installing a 1 star security cylinder with a 2 star handle which gives you a combined score of 3 stars.

For advice on cylinder snapping, visit our cylinder snapping page.


Key-Operated Security Bolts

These are suitable for wooden doors and are ideal for back doors. They provide additional security and can be operated from inside.

Advantages of a Security Bolt

Ease: Can be easily fitted to a door to provide security.

Disadvantages of a Security Bolt

Security: Does not hold great security

Fitting: Needs to be fitted correctly on different types of doors to secure it.



Master padlock


Padlocks are portable locks that are usually smaller in size and can be used to secure a multitude of items both in and outdoors. There are several different types of padlocks including; closed shackle chains, shutters, open shackle, straight shackle and long shackle. Padlocks can be useful for an extra level of security and are perfect to use when mobile to secure personal items.

Advantages of a Padlock

External Security: They are the perfect solution for outdoor security including securing sheds and gates.

Ease: They are easy to secure and operate.

Security: You can get higher security models that are closed shackled making it harder to force open, and can get high end models that can use fingerprint to open.

Variety: You can get many different variations of padlocks that range in security and price to suit your individual needs and wants.


Disadvantages of a Padlock

Security: The lower budget models have lower security and can be broken into easily with bolt cutters or a saw.


Cam Locks

A cam lock is mostly found on furniture or cabinets within a property with good external security. Usually smaller in statue, they offer an extra level of protection for valuables in the home or office.


Advantages of a Cam Lock

Security: They are the perfect solution to add security to private and valuable items within the home and office.


Disadvantages of a Cam Lock

Security: With force can easily be opened.

Hopefully this guide has helped you decide which lock is best for your needs and you should now know the difference between a mortice lock and a multi-point locking system. If you feel that you require more advice when it comes to home security then you can receive a free home security check, by a Keytek® Locksmith when they do any other work on your property. Always make sure that your locks are compliant with your insurance policy, to avoid any issues if you get burgled. Please view our frequently asked questions if you have any more queries.

If you have any questions about Locksmith prices please visit our Locksmith Prices advice page.

Door Lock Types Quick Identifiers

How to Identify a Euro Cylinder Locks

The euro lock cylinder is fairly common and is frequently found installed on UPVC doors in conjunction with a multi-point locking system. They can also be fitted to some mortice deadlocks and sashlocks on timber and aluminium doors.

How to Identify a Multi-Point Locking System

A Multipoint locking system will be fitted into the body of the door and it locks into the door frame. When you lock a multipoint locking system using a key, it will engage multiple bolts into the door frame. There should be a minimum of 3 and often there are 4 or 5 locking points. These types of locks are mostly found on UPVC doors, but are also used on French or Patio doors. Although they are mostly found on UPVC doors, Multi-point locking systems can be installed on timber and Aluminium doors.

How to Identify a Rim Cylinder

A Rim Cylinder is part of a Rim nightlatch system or a Yale type lock. They are found on wooden doors and they are the outer part of the lock that you use to open the door with a key. Popular brands of Rim Cylinder include Yale, ERA, Mul-T-Lock, Eurospec and Union.

How to Identify a Multi-Point Locking System

A Multipoint locking system will be fitted into the body of the door and it locks into the door frame. When you lock a multipoint locking system using a key, it will engage multiple bolts into the door frame. There should be a minimum of 3 and often there are 4 or 5 locking points. These types of locks are mostly found on UPVC doors, but are also used on French or Patio doors. Although they are mostly found on UPVC doors, Multi-point locking systems can be installed on timber and Aluminium doors.

How to Identify a 5 Lever Mortice Deadlock

Mortice Deadlocks are not found on uPVC or composite doors, they will be found on wooden doors. You will be able to open it with a key from both sides of the door. A Mortice Deadlock won’t be fitted to the actual surface of the door, but to the leading edge of the door. If you do have a 5 Lever Mortice Deadlock then the number of leavers should be stamped on the faceplate.


We have answered some Frequently Asked Questions, to help you when picking the lock that is right for you.

A deadlock or ‘deadbolt’ is the bolt that throws across from a mortice lock into the frame – it can only be switched to an open position by rotating the key.

This is a mortice lock – usually fitted to a door in addition to other locks. They are available in a British Standard version – which is usually the requirement for all external doors to a property.

This is a mortice lock with an accompanying handle.

This is dependent on whether it is a British Standard version or the regular version – the 5 lever British Standard version will have an extra armoured plate on the side, a ‘curtain’ around the keyway and also the bolt will throw out of the lock by 20mm minimum. If any of these features are not present then it will be just a plain 5 Lever Mortice deadlock; or lower security standard type deadlock.

A MPL or ‘Multipoint Lock’ is the mechanism which fits into the side of the door, having a central gearbox built into it as well as various types of ‘Locking Points’ at varying positions along its length. They vary greatly but almost all uPVC doors require them in order to secure a property as well as many other types of doors too.

Look for the BSI (British Standard Institute) kitemark on the lock itself.