The Master Key System: How Do Master Key Systems Work?

A master key system is somewhat popular among property owners. The system has been known to improve security and significantly increase control over the respective property. Under the master key system, different predefined doors are created to be conveniently accessed by select keys. This system allows the owners of properties to lower expenses caused by multiple keys being required.

The master key system is structured into two levels of keying. The master key is considered the most powerful key level in this system. It unlocks all lock locks and doors within the system. Alternatively, sub-master keys open specific locks. In some cases, they can open only one particular lock. This system’s primary structure makes it perfect for properties and buildings that have several restricted areas for specific groups of people.

In this article, discover all you need to know before integrating the master key system into your property.

What is a Master Key?

A master key is a key that can be used to open different locks. People often believe they have a master key because the key works with different door locks in their house. In reality, the locks in their homes are keyed alike, making it easy for similar keys to open the locks. Typically, a master key overrides every lock in a system, no matter the design. Even though none of the keys available in the system may fit each other, the master key grants access to all locks.

Five Things You Need to Know About a Master Key System Security

1. The locks offered are re-keyable

Rekeyable locks are included in the master key system to save property owners the stress of calling a locksmith company to change the locks.

If any of the master keys fall into the hands of strangers or unauthorized personnel, the re-keyable lock technology allows the property to remain secure and safe. It also makes the building’s entire operation continuous, cutting out delays and setbacks due to a compromised lock or key.

2. Key copying is prevented  

Master keys give you access to all doors within a particular system. This means that if the master key falls into the wrong hands, they can easily unlock every door. The good news is that with master key systems, key copying is prevented. All keys under the system are created on a restricted keyway, preventing key copying without the revelation authorization.

3. You have the option of key tracking

One very important feature of many master key systems is easily tracking and managing all the keys within the system. Some systems have extremely secure control software, safe from online threats, allowing owners to manage their keys. This key tracking feature enabled homeowners to secure their property even when they are far away.

4. Key security is guaranteed

Certain keys are designed to grant access to all areas of particular properties. Such a setup implies that these keys must remain secure, no matter the circumstances. With the services offered by locksmith Toronto experts, the ownership and condition of master keys can be secured using an integrated, unique serial number.

This serial number holds information such as the doors and locks that the key can access freely, the key owner’s identity, and so on. This information is tracked constantly, ensuring that the keys remain in the hands of authorized personnel.

5. Master keys are convenient

Master keys eliminate the need for a massive bunch of keys. Carrying around different keys for different doors in an apartment building or office complex can be exhausting.

In an emergency, master locks can be opened conveniently using a single key. For maintenance purposes, superintendents, managers, and security guards can use a single key to open and close all the building doors.

Master keys also give you the option of varying security levels with sub-master keys that provide access to a specific set of locks.

Can a Locksmith Set-up a Master Key System?

Yes, a locksmith can make a master key. If you need to set up a master key system, you can contact an expert locksmith Toronto to help set it up.

How Much Does a Master Key System Cost?

A master key system’s cost depends on several factors, such as how many keys are needed and how many doors will be keyed.

Some factors that determine how much you will spend on a master key include:

  • How many areas require special restrictions/access
  • How many copies of keys you need
  • The various types of keys you need
  • The number of doors in your system
  • The complexity and size of your system

Generally, a simple system begins at about $30. Considering the convenience and extra security of a master key system, this is a small price to pay.

Can a Master Key Open Any Lock?

Yes, a master key can open all locks in a system. No, a master key cannot open every similar lock, except the manufacturer builds that feature in.

A modern pin tumbler lock system with the same type of lock throughout can be set up using master pinning. This type of pinning will allow a master key to open any available lock in the system. However, this does not mean that the same master key from building A will open similar locks in building B.

With the warded lock system, you may be able to configure one key to unlock all doors, while individual keys can only unlock one or two select doors. You may find that your master key opens other locks from the same manufacturer, depending on the level of thought put in the designs.

How Do You Tell if a Key is a Master Key?

A master key opens all the locks in a particular system. If you have a key that has been fashioned or designed to grant access to every lock in a system, it is a master key. Master keys should not be mistaken for keys that can open like locks. A true master key will override the system, irrespective of design.

How Do Master Key Systems Work?

Types of Master Key Systems
Types of Master Key Systems

There are several keys in a master system, offering different levels of access. They include:

Great Grand Master Key

This master key will grant access to all grand master key systems under it. It will also offer access to the master key systems under the grandmaster keys and the change keys.

Grand Master Key

A grandmaster key grants access to multiple master key systems. This master key opens all the master systems under it, and subsequently, the change keys under those systems.

Master Key

This is the main component that transforms a basic lock into a master keyed lock. Without this key, individual locks have their keys. Some master key systems consider this the highest-ranking key.

Change key

The change key is also known as a sub-master key. This key will only open one lock and replica locks. A master key and other keys above that rank can also be used in opening the lock that the change key opens.

Components of a Master Key


You will find skinny cylinders that move up and down. Usually, there are two pins, one below the line in the lock’s center and one above.

Shear line

The shear line is the straight line that goes through the center of the lock. The shear line creates the space needed for the lock to turn when the pins line up.

Key notches

At the key’s jagged edge, you will notice notches designed to match the pins contained in the cylinder. What differentiates a master key from other keys is that their locks have a third pin. This third pin is called a master wafer and can only be unlocked by a master key.

Usually, master key systems operate off a simple pin tumbler lock. A pin stack made up of a key pin and driver pin must be elevated to open this type of lock. This elevation will allow the two pins to rest opposite the shear line. When a key is inserted, it lifts key pins within a lock. These key pins are in varying sizes, but the driver pins are usually a universal size.

Therefore, to lift the key pins to the required height, the key needs to have the right set of grooves. All you need to convert a standard pin tumbler to a master key system is a master pin. More commonly known as s master wafer, this is a small hockey pick shaped pin placed between a key and driver pin.

Once the master wafer is in place, the pin stack will branch into two shear lines. One of the shear lines will hold a pin stack, with its master wafer located above it below the line.


If you live in Toronto or the GTA and search for a professional master key system setup, check out TBC Locksmith. We provide expert solutions to all your locksmith needs, including top-notch door repairs, installing new locks, making new keys, and rekeying locks.

You must have access to the right security solution for your property. You need a locksmith company you can trust for both regular and emergency services. We are available 24/7 with a 15-30 minute response time, so do not hesitate to give us a call today.


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