Master lock and key system diagram.

Your locks can be one of the best lines of defence for your home or business. According to a survey, burglars reported that minimal security, open doors and windows, poor security systems and detectable keys were all top reasons for break-in attempts.

While you cannot necessarily foil all potential criminals, you can take steps to reduce the risk with a secure lock-and-key system. A Master Lock System can simplify the process for you and your business.

What Is a Master Lock System?

The Master Lock System, which is also known as a Master Key System, is a special locking system that provides a specific level of access for each set of keys. The key with the highest level of access will open all the doors in a specific facility while the other keys will have access to specific doors depending on their authorisation level.

Master key systems diagram of how it works.

Master Lock Systems: The Basics

With other key systems, each employee would have keys for their specific offices, rooms or spaces. Employees, such as office managers, who needed access to multiple areas, could find themselves carrying around multiple keys on large rings. This would be bulky, cumbersome and inconvenient. If a key was lost, it might not even be noticed right away and could be difficult to track down.

Worse, as people come and go or buildings and locks change, keys can get lost or become obsolete. With new staff, new responsibilities and new growth, the keyring grows, and more time is spent looking for just the right key to unlock the doors.

At this point, a standard door lock system can become a serious security risk because people start leaving their doors unlocked or sharing keys. People come and go with little oversight or accountability.

With a Master Lock System, each person has his or her own key, eliminating the issues associated with individual keys, including:

  • The frustration and confusion of juggling keyrings
  • The risks of losing a key
  • The dangers of leaving rooms and buildings unlocked entirely.

Master Lock Systems Keep Buildings, Rooms and People Safe

Senior staff will have their keys unlocking each or most doors in their offices or company.

These keys can typically be designed to unlock:

  • Deadbolts and padlocks
  • Warehouses
  • Storerooms
  • Offices
  • Staff areas
  • Departments
  • Individual doors
  • Office buildingsDepartment heads and office managers will have keys to unlock their specific offices or departments, and individual employees will have keys for their offices and any other areas for which they are responsible.

Master lock and key system diagram.

Does a Master Lock System Require More Keys?

A Master Lock System reduces the number of keys you need to juggle. Having more keys, or a key for each lock might sound like a good idea at first. However, that also means more keys to get lost or mixed up. Ultimately, it can increase your risk and vulnerability to break-ins and loss.

With a Master Key System, you can increase your level of security by having fewer keys. Each person can manage his or her own key. With just one key to keep track of for all accessible rooms and areas, the risk of loss or misuse is significantly lowered. If that one key is lost or stolen, the risk can be contained faster by quickly and efficiently rekeying the compromised locks.

Master keys being cut by a machine.

Types of Keys in a Master System

There can be several keys involved in a Master Key system, each offering varying degrees of access according to your needs, including:

Master Key

This is typically the highest-ranking key in a Master Key System, and it will open all the locks in a system.

Sub Master Key

This key can also be called the change key, and it will only open specific locks that are at that specific level of access. These locks can also be opened by the Master Key.

Some systems include higher levels of access that necessitate further keys, including Grand Master keys, which will open additional Master Key Systems.

What Kind of Locks Are Needed for a Master System?

Master Lock Systems can use a variety of locks and keys. However, the majority use basic pin tumbler locks. Pin tumbler locks work a little like a puzzle. The grooves in the driver pins of the lock must match up with the grooves in the key before the lock will open. If the level of access is appropriate, the key will turn, and the lock will open.

How Are Locks Master Keyed?

Conventional lock cylinders that use one key have a set of pins on the bottom and a set of pins on the top. When the correct key is inserted, the keys create a shear line along the cylinder, freeing it from the pins and allowing it to turn freely.

Master keyed cylinders have additional sets of pins. This enables them to be used with multiple sets of keys. The pins are stacked, creating different shear lines.

In a Master Lock System, only some of the keys have all the grooves needed to fit each pin in the lock. The system is graduated so that the level of access can be adjusted according to need. When a dual combination key is used, there can be up to 17 million locking combinations. Keys can be colour coded to ensure a visual backup for the level of access.

Are Master Lock Systems Really Safe?

Some of the most secure systems in the world use Master Key Systems. High-security Master Key systems are used in some of the best-protected areas in the world and for a good reason: They are extremely safe and secure.

A single “master key” is used to operate all locks while other keys will operate specific locks depending on the amount of access granted. There can also be an overriding Master Key that grants universal access.

Only authorised signatories are eligible to order new keys, ensuring that all keys are properly accounted for. You will always have full control over the issue and quantity of keys.

Master Keys work with a wide range of systems, including:

  • Abloy Pro
  • Binary Plus
  • Galaxy
  • Kaba Expert
  • Generation 6
  • Lockwood Twin
  • Status 6They can even be tied into your electronic access control via card and keypads.

The Benefits of a Master Lock System


A Master Lock System offers multiple benefits to your business, including greater security, convenience and affordability.

Greater Security

With a Master Key System, access can be restricted as needed. Individuals will have keys that allow them entry only to the areas to which they need to have access. Their keys will not provide entry to any other area to which they do not have access.

If an employee quits or is terminated, only their level of access will need to be rekeyed. Even rekeying can be avoided when a restricted key system is used.

Restricted keys are keys that can only be sold and duplicated through specific companies or locksmiths, eliminating the risk of the key being duplicated. The key cannot be duplicated without prior authorisation through the company. This saves you and your organisation the expense of having to rekey any locks when an employee is let go.


Having to carry around numerous keys and remember which key goes to which cabinet, door, storeroom or locker can get complicated. Trying to simplify the process through colour coding or other systems might not help much. With a Master Key System, you only have one key to keep track of, and that single key will open every door you need to access.

Whether you are a clerk, an office manager, senior staff or the owner, you will need just one key.


The financial benefits of a Master Key System might not be obvious immediately, but they add up over time. If a key needs to be replaced when staff changes or a key is lost, the entire system does not need to be rekeyed. Instead, the individual lock can be changed. This can significantly lower costs without interfering with critical access needs.

What Is the Process for Installing a Master Lock System?

At Diamond Lock and Security, our goal is to provide you with a fully customised system that works for you. We start by surveying your doors and locks and identifying the best way to meet your needs. Next, we will design and install your system based on your goals and preferences.

What to Expect from Your Installation

If you decide that a Master Key System is right for you, our Diamond Lock and Security experts will sit down with you to plan out your system. A simple system can be mapped out in a few minutes, but a more complex system will take time and planning.

Our team begins by developing a lock access floor plan based on your information, ensuring that each member of your staff has access to the appropriate doors and locks. We will take care to ensure that keys for one set of doors will not inadvertently open any other doors. To do this, we will provide key charts with specific cuts for the different levels of access.

Once your keys and locks have been manufactured, we will deliver and install them. We can even include a Key Management program to ensure you have better control over access.

Will We Need New Hardware?

Rarely, if your building is particularly old or if you want additional padlocks added, you might need some new hardware included. However, in many cases, you might not need any new hardware.

Maintaining Your Master Lock System

Once your new system is in place, you will need to maintain and manage it. Keeping your system secure is largely a matter of ensuring the keys and locks are in good condition. If a key or a lock is damaged, contact Diamond Lock and Security right away. We will make the necessary repairs and get you back in working order as soon as possible. If you have many keys involved in your system, we can customise a solution that fits your needs.

Experience Where It Counts

Diamond Lock and Security are proud industry leaders. We are experts in the field of Master Key Systems, using only high-security locks and standard or restricted keys. Our team can help you develop a fully customised security system, including:

  • Electric locks and strikes
  • CCTV systems
  • Access control systems
  • Lock installation
  • Intercoms
  • And more
    We can ensure that your system grows with you without ever compromising on safety or security. Contact our team to learn more or schedule a security evaluation today.

A team of locksmiths standing out the front of Diamond Lock and Security office and workshop.

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