Commercial Security • Perth

How Long Does a Master Key System Last Before It Needs Replacing?

The hardware can run for 15 to 20 years. The security behind it can quietly fall apart in two to five. Here's why, and how to tell which stage yours is at.

Here's the honest answer: the hardware in a well-made restricted master key system can run for 15 to 20 years, sometimes longer. But the security of that system can quietly fall apart in as little as two to five years, and it's almost never the locks themselves that cause the problem.

If you manage an office or a multi-tenant building, that gap matters. Your locks can look fine while half the keys are copies that nobody is tracking.

Quick Answer

Well-maintained lock hardware typically lasts 15+ years mechanically.
The system's actual security often degrades much sooner, usually because keys have been copied without control.
Restricted key systems close that gap by stopping unauthorised duplication.
Signs you need to replace or rekey: worn cylinders, a lost master key, or simply not knowing how many keys exist anymore.

The Hardware Usually Outlasts the System

Hardware lifespan

15 to 20+ years

Lock cylinders are built to take a beating. Good commercial-grade hardware, kept clean and lubricated, can mechanically function for decades.

Security lifespan

2 to 5 years

Without control over duplication, it's hard to say with confidence who holds a working key after a year or two, let alone five.

If your locks feel stiff or unreliable after only a few years, that usually points to cheap components or poor installation, not old age.

The catch is that a master key system isn't really "the locks." It's the whole structure behind them: who holds which key, what each one opens, and how tightly that's controlled. That structure can break down long before the metal does.

The Real ProblemWhat Actually Kills a Master Key System Early

In most cases, it comes down to one thing: standard keys can be copied anywhere. A staff member gets a spare cut at a hardware store. A contractor keeps their key "just in case." A tenant moves out and nobody asks for it back.

None of that shows up as a mechanical fault. Your locks still turn perfectly. But you've quietly lost track of who can get in, and that's the real point where a system stops being secure, even though it looks unchanged from the outside.

This is why standard, non-restricted master key systems tend to have a short useful life. Without control over duplication, it's hard to say with confidence who holds a working key after a year or two, let alone five.

How Restricted Key Systems Extend the Lifespan

Restricted key systems tackle this at the source. The key profile is patented or registered, so copies can only be cut by an authorised locksmith with your sign-off, not at any kiosk or hardware counter.

Standard master key

Keys can be copied at any kiosk
No record of how many exist
Security lifespan of a couple of years

Restricted master key

Copies only with your written sign-off
Accurate count of every key and who holds it
Stays trustworthy for as long as the hardware lasts

That one change does a lot of heavy lifting. Restricted master key systems give you an accurate picture of exactly how many keys exist and who holds them, for as long as the system's in place. Instead of a security lifespan measured in a couple of years, you get a system that stays trustworthy for as long as the hardware lasts.

For any building with staff turnover, contractors, or tenants coming and going, restricted key systems aren't really an upgrade. They're what makes a master key system worth having.

Signs It's Time to Replace or Rekey

You genuinely don't know how many keys are in circulation.
A master key has gone missing, not just a single-door key.
Cylinders are sticking, grinding, or need jiggling to turn.
Staff or tenants have moved on with no key-return process.
The system was never restricted to begin with.

One of these is worth a call. A few together, and it's time to stop patching and plan a proper rekey.

Getting the Most Out of Your System

A well-designed, restricted setup is one of the more sensible investments a business can make. Get it right and you won't be revisiting it for years. Gronbek Security has been designing master key systems for Perth businesses since 1981, and we can tell you quickly whether yours needs full replacement or just tighter key control.

It's one part of the broader security solutions we handle across Perth. If your keys have been floating around longer than you'd like to admit, call us and we'll talk you through what a properly restricted system would look like for your building.